diff --git a/AtCoder/ABC309/B/B.cpp b/AtCoder/ABC309/B/B.cpp
new file mode 100644
index 00000000..e99f34fd
--- /dev/null
+++ b/AtCoder/ABC309/B/B.cpp
@@ -0,0 +1,56 @@
+#include <iostream>
+#include <string>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 105;
+
+int n;
+std::string a[N], b[N];
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n;
+
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+
+        b[i] = a[i] = ' ' + a[i];
+    }
+
+    for (int i = 2; i <= n; i++) {
+        b[1][i] = a[1][i - 1];
+    }
+
+    for (int i = 1; i < n; i++) {
+        b[i][1] = a[i + 1][1];
+    }
+
+    for (int i = 1; i < n; i++) {
+        b[n][i] = a[n][i + 1];
+    }
+
+    for (int i = 2; i <= n; i++) {
+        b[i][n] = a[i - 1][n];
+    }
+
+    for (int i = 2; i < n; i++) {
+        for (int j = 2; j < n; j++) {
+            b[i][j] = a[i][j];
+        }
+    }
+
+    for (int i = 1; i <= n; i++) {
+        for (int j = 1; j <= n; j++) {
+            cout << b[i][j];
+        }
+
+        cout << endl;
+    }
+
+    return 0;
+}