#include <iostream>

int matrix[20][20];
int m, n;

void vvod()
{
    std::cout << "m: ";
    std::cin >> m;

    std::cout << "n: ";
    std::cin >> n;

    std::cout << "\nVvedite elementi:\n";
    for (int i = 0; i < m; ++i)
        for (int j = 0; j < n; ++j)
            std::cin >> matrix[i][j];
}

void obrabotka()
{
    for (int i = 0; i < m; ++i)
        for (int j = 0; j < n; ++j)
            if (matrix[i][j] == i)
                matrix[i][j] = 7;
}

void vivod()
{
    std::cout << "\nVivod\n";
    for (int i = 0; i < m; ++i) {
        for (int j = 0; j < n; ++j)
            std::cout << matrix[i][j] << " ";

        std::cout << "\n";
    }
}

int main()
{
    vvod();
    obrabotka();
    vivod();

    return 0;
}