#include <iostream>

using namespace std;

int main() {

    int m;
    cin >> m;



    for(int i = 1; i <= m; i++) {
        for(int j = 1; j <= m; j++) {
            if(i == 1 || i == m) {
                if(j == 1 || j == m) {
                    cout << "%";
                }
                else {
                    cout << "@";
                }
            }
            else {
                if(j == 1 || j == m) {
                    cout << "%";
                }
                else {
                    cout << ".";
                }

            }
        }
        cout << "\n";
    }

    return 0;
}