void f1(int **arr, int n, int m){
    for(int i = 0; i < n; ++i){
        for(int j = 0; j < m; ++j){
            arr[i][j] = i * j;
        }
    }
}

void f2(int **arr, int n, int m){
    for(int i = 0; i < n; ++i){
        for(int j = 0; j < m; ++j){
            cout << arr[i][j] << endl;
        }
    }
}

int main(){
    int n = 2, m = 3;
    int **arr = new int *[n];

    for(int i = 0; i < n; ++i){
        int *arr = new int[m];
    }

    f1(arr, n, m);
    f2(arr, n, m);

}