diff --git "a/week16/BOJ_1_20115/\353\260\225\355\235\254\352\262\275_20115.java" "b/week16/BOJ_1_20115/\353\260\225\355\235\254\352\262\275_20115.java"
new file mode 100644
index 0000000..37134fe
--- /dev/null
+++ "b/week16/BOJ_1_20115/\353\260\225\355\235\254\352\262\275_20115.java"
@@ -0,0 +1,30 @@
+package BOJ_1_20115;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.StringTokenizer;
+
+public class 박희경_20115 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st;
+
+        int N = Integer.parseInt(br.readLine());
+        int[] arr = new int[N];
+
+        int max = 0;
+        st = new StringTokenizer(br.readLine());
+        for(int i = 0; i < N; i++) {
+            arr[i] = Integer.parseInt(st.nextToken());
+            max = Math.max(arr[i], max);
+        }
+        double res = max;
+        for(int i = 0; i < N; i++) {
+            if(arr[i] == max)
+                continue;
+            res += arr[i]/2.0;
+        }
+        System.out.println(res);
+    }
+}
diff --git "a/week16/BOJ_2_12933/\353\260\225\355\235\254\352\262\275_12933.java" "b/week16/BOJ_2_12933/\353\260\225\355\235\254\352\262\275_12933.java"
new file mode 100644
index 0000000..8c57f62
--- /dev/null
+++ "b/week16/BOJ_2_12933/\353\260\225\355\235\254\352\262\275_12933.java"
@@ -0,0 +1,39 @@
+package BOJ_2_12933;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+public class 박희경_12933 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        String str = br.readLine();
+
+        int[] arr = new int[6];
+        int size = str.length();
+        int max = 0;
+        arr[0] = size;
+
+        for(int i = 0; i < size; i++) {
+            int n = 0;
+            if(str.charAt(i) == 'q') n = 1;
+            if(str.charAt(i) == 'u') n = 2;
+            if(str.charAt(i) == 'a') n = 3;
+            if(str.charAt(i) == 'c') n = 4;
+            if(str.charAt(i) == 'k') n = 5;
+            if(arr[n - 1] == 0) {
+                System.out.println("-1");
+                return;
+            }
+            arr[n]++;
+            arr[n - 1]--;
+            max = Math.max(max, arr[1] + arr[2] + arr[3] + arr[4]);
+        }
+
+        if(arr[5] * 5 != size) {
+            System.out.println("-1");
+            return;
+        }
+        System.out.println(max);
+    }
+}
diff --git "a/week16/BOJ_5_21921/\353\260\225\355\235\254\352\262\275_21921.java" "b/week16/BOJ_5_21921/\353\260\225\355\235\254\352\262\275_21921.java"
new file mode 100644
index 0000000..add68dc
--- /dev/null
+++ "b/week16/BOJ_5_21921/\353\260\225\355\235\254\352\262\275_21921.java"
@@ -0,0 +1,53 @@
+package BOJ_5_21921;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.StringTokenizer;
+
+public class 박희경_21921 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        int N = Integer.parseInt(st.nextToken());
+        int X = Integer.parseInt(st.nextToken());
+
+        int[] arr = new int[N];
+
+        st = new StringTokenizer(br.readLine());
+        for(int i = 0; i < N; i++){
+            arr[i] = Integer.parseInt(st.nextToken());
+        }
+
+        int end = 0;
+        int sum = 0;
+        int max = 0;
+        int count = 1;
+
+        for(int i=0; i < N; i++){
+            while((end - i < X) && end < N){
+                sum += arr[end];
+                end++;
+            }
+
+            if(max == sum){
+                count++;
+            }
+            else if(max < sum){
+                max = sum;
+                count = 1;
+            }
+
+            sum -= arr[i];
+        }
+
+        if(max == 0){
+            System.out.println("SAD");
+            return;
+        }
+
+        System.out.println(max);
+        System.out.println(count);
+    }
+}