#include <cstdint>
#include <iostream>
#include <string>
#include <vector>

int main() {
    int32_t r, c;
    std::cin >> r >> c;
    std::vector<std::string> grid(r);
    for (auto& row : grid) {
        std::cin >> row;
    }

    std::string ans;
    for (int32_t j = 0; j < c; ++j) {
        for (int32_t i = 0; i < r; ++i) {
            if (grid[i][j] != '.')
                ans += grid[i][j];
        }
    }

    std::cout << ans << '\n';
}