diff --git a/ABC451/cnvxlns/A.cpp b/ABC451/cnvxlns/A.cpp
new file mode 100644
index 0000000..34778c0
--- /dev/null
+++ b/ABC451/cnvxlns/A.cpp
@@ -0,0 +1,48 @@
+#include<bits/stdc++.h>
+
+#define int long long
+#define endl "\n"
+
+using namespace std;
+using vi = vector<int>;
+using vvi = vector<vi>;
+using pii = pair<int, int>;
+using tiii = tuple<int, int, int>;
+using vpii = vector<pii>;
+
+const int inf = 4e18;
+const int MOD = 1e9 + 9;
+
+vpii drc = {{1, 0}, {0, -1}, {-1, 0}, {0, 1}};
+
+pii operator+(pii A, pii B){
+    return {A.first + B.first, A.second + B.second};
+}
+pii operator-(pii A, pii B){
+    return {A.first - B.first, A.second - B.second};
+}
+
+void init(){
+
+}
+
+void solve(){
+    string s;
+    cin >> s;
+    if(s.size() % 5 == 0){
+        cout << "Yes" << endl;
+    }else{
+        cout << "No" <<endl;
+    }
+}
+
+int32_t main(){
+    cin.tie(0)->sync_with_stdio(0);
+    init();
+    int t = 1;
+    // cin >> t;
+    while(t--)
+        solve();
+
+    return 0;
+}
diff --git a/ABC451/cnvxlns/A.py b/ABC451/cnvxlns/A.py
new file mode 100644
index 0000000..07376c6
--- /dev/null
+++ b/ABC451/cnvxlns/A.py
@@ -0,0 +1,36 @@
+import sys
+import math
+import heapq
+from collections import deque, defaultdict, Counter
+from itertools import permutations, combinations, product
+from bisect import bisect_left, bisect_right
+
+sys.setrecursionlimit(int(1e6))
+inf = math.inf
+input = sys.stdin.readline
+
+MOD = 1e9 + 7
+
+drc = [(-1, 0), (0, 1), (1, 0), (0, -1)]
+
+def init():
+
+    return
+
+def solve():
+    s = input()
+    print(len(s))
+    if len(s) % 5 == 0:
+        print("Yes")
+    else:
+        print("No")
+    return 
+
+if __name__ == "__main__":
+    init()
+    t = 1
+    # t = int(input())
+    while t:
+        t -= 1
+        solve()
+        
\ No newline at end of file
diff --git a/ABC451/cnvxlns/B.cpp b/ABC451/cnvxlns/B.cpp
new file mode 100644
index 0000000..5f58551
--- /dev/null
+++ b/ABC451/cnvxlns/B.cpp
@@ -0,0 +1,53 @@
+#include<bits/stdc++.h>
+
+#define int long long
+#define endl "\n"
+
+using namespace std;
+using vi = vector<int>;
+using vvi = vector<vi>;
+using pii = pair<int, int>;
+using tiii = tuple<int, int, int>;
+using vpii = vector<pii>;
+
+const int inf = 4e18;
+const int MOD = 1e9 + 9;
+
+vpii drc = {{1, 0}, {0, -1}, {-1, 0}, {0, 1}};
+
+pii operator+(pii A, pii B){
+    return {A.first + B.first, A.second + B.second};
+}
+pii operator-(pii A, pii B){
+    return {A.first - B.first, A.second - B.second};
+}
+
+void init(){
+
+}
+
+void solve(){
+    int N, M;
+    cin >> N >> M;
+    vi A(N), B(N);
+    vi members1(M + 1, 0), members2(M + 1, 0);
+    for(auto i = 0; i < N; ++i){
+        cin >> A[i] >> B[i];
+        members1[A[i]]++;
+        members2[B[i]]++;
+    }
+    for(auto i = 1; i <= M; ++i){
+        cout << members2[i] - members1[i] << endl;
+    }
+}
+
+int32_t main(){
+    cin.tie(0)->sync_with_stdio(0);
+    init();
+    int t = 1;
+    // cin >> t;
+    while(t--)
+        solve();
+
+    return 0;
+}
diff --git a/ABC451/cnvxlns/C.cpp b/ABC451/cnvxlns/C.cpp
new file mode 100644
index 0000000..a91146b
--- /dev/null
+++ b/ABC451/cnvxlns/C.cpp
@@ -0,0 +1,54 @@
+#include<bits/stdc++.h>
+
+#define int long long
+#define endl "\n"
+
+using namespace std;
+using vi = vector<int>;
+using vvi = vector<vi>;
+using pii = pair<int, int>;
+using tiii = tuple<int, int, int>;
+using vpii = vector<pii>;
+
+const int inf = 4e18;
+const int MOD = 1e9 + 9;
+
+vpii drc = {{1, 0}, {0, -1}, {-1, 0}, {0, 1}};
+
+pii operator+(pii A, pii B){
+    return {A.first + B.first, A.second + B.second};
+}
+pii operator-(pii A, pii B){
+    return {A.first - B.first, A.second - B.second};
+}
+
+void init(){
+
+}
+
+void solve(){
+    int Q;
+    cin >> Q;
+    multiset<int> ms;
+    while(Q--){
+        int q, h;
+        cin >> q >> h;
+        if(q == 1){
+            ms.insert(h);
+        }else{
+            ms.erase(ms.begin(), ms.upper_bound(h));
+        }
+        cout << ms.size() << endl;
+    }
+}
+
+int32_t main(){
+    cin.tie(0)->sync_with_stdio(0);
+    init();
+    int t = 1;
+    // cin >> t;
+    while(t--)
+        solve();
+
+    return 0;
+}
diff --git a/ABC451/cnvxlns/D.cpp b/ABC451/cnvxlns/D.cpp
new file mode 100644
index 0000000..2729604
--- /dev/null
+++ b/ABC451/cnvxlns/D.cpp
@@ -0,0 +1,89 @@
+#include<bits/stdc++.h>
+
+#define int long long
+#define endl "\n"
+
+using namespace std;
+using vi = vector<int>;
+using vvi = vector<vi>;
+using pii = pair<int, int>;
+using tiii = tuple<int, int, int>;
+using vpii = vector<pii>;
+
+const int inf = 4e18;
+const int MOD = 1e9 + 9;
+
+vpii drc = {{1, 0}, {0, -1}, {-1, 0}, {0, 1}};
+
+pii operator+(pii A, pii B){
+    return {A.first + B.first, A.second + B.second};
+}
+pii operator-(pii A, pii B){
+    return {A.first - B.first, A.second - B.second};
+}
+
+vector<string> pieces;
+set<int> ans;
+
+string inttostr(int num){
+    string ret = "";
+    while(num > 0){
+        char n = (num % 10) + '0';
+        ret += n;
+    }
+    return ret;
+}
+
+int stringtoint(string num){
+    int ret = 0;
+    for(auto i: num){
+        ret *= 10;
+        ret += i - '0';
+    }
+    return ret;
+}
+
+void dfs(string val){
+    if(val.size() > 10){
+        return ;
+    }
+    ans.insert(stringtoint(val));
+    for(const auto &i: pieces){
+        dfs(val + i);
+    }
+}
+
+void init(){
+    for(auto i = 1; i <= (1 << 29); i *= 2){
+        if(i == 128){
+            continue;
+        }
+        pieces.push_back(inttostr(i));
+    }
+    for(auto i: pieces){
+        dfs(i);
+    }
+}
+
+void solve(){
+    int N;
+    cin >> N;
+    int cnt = 0;
+    for(auto i: ans){
+        if(cnt++ > N){
+            cout << i << endl;
+            return ;
+        }
+    }
+}
+
+int32_t main(){
+    cin.tie(0)->sync_with_stdio(0);
+    init();
+    int t = 1;
+    // cin >> t;
+    while(t--)
+        solve();
+
+    return 0;
+}
diff --git a/ABC451/cnvxlns/D_AC.cpp b/ABC451/cnvxlns/D_AC.cpp
new file mode 100644
index 0000000..1008acf
--- /dev/null
+++ b/ABC451/cnvxlns/D_AC.cpp
@@ -0,0 +1,75 @@
+#include<bits/stdc++.h>
+
+#define int long long
+#define endl "\n"
+
+using namespace std;
+using vi = vector<int>;
+using vvi = vector<vi>;
+using pii = pair<int, int>;
+using tiii = tuple<int, int, int>;
+using vpii = vector<pii>;
+
+const int inf = 4e18;
+const int MOD = 1e9 + 9;
+
+vpii drc = {{1, 0}, {0, -1}, {-1, 0}, {0, 1}};
+
+pii operator+(pii A, pii B){
+    return {A.first + B.first, A.second + B.second};
+}
+pii operator-(pii A, pii B){
+    return {A.first - B.first, A.second - B.second};
+}
+
+vector<string> pieces;
+set<int> ans;
+
+void dfs(string val){
+    ans.insert(stoll(val));
+    
+    for(const auto &i: pieces){
+        if(stoll(val + i) > 1e9){
+            continue;
+        }
+        dfs(val + i);
+    }
+}
+
+void init(){
+    for(auto i = 1; i <= (1 << 29); i *= 2){
+        if(i == 128){
+            continue;
+        }
+        pieces.push_back(to_string(i));
+    }
+    for(auto i: pieces){
+        dfs(i);
+    }
+}
+
+void solve(){
+    int N;
+    cin >> N;
+    int cnt = 0;
+    
+    for(auto i: ans){
+        if(cnt == N - 1){
+            cout << i << endl;
+            return ;
+        }
+        cnt++;
+    }
+}
+
+int32_t main(){
+    cin.tie(0)->sync_with_stdio(0);
+    init();
+    
+    int t = 1;
+    // cin >> t;
+    while(t--)
+        solve();
+
+    return 0;
+}
\ No newline at end of file