#include <iostream>
int main() {
    int height;
    char at = '@';
    std::cout << "Enter a height: ";
    std::cin >> height;
    for (int i = 0, j = 1;i < height;i++, j *= 2) {
        for (int k = 0;k < j;k++) {
            std::cout << at;
        }
        std::cout << std::endl;
    }
    return 0;
}