6_6_2

#include <stdio.h>

int sum(int *arr, int *end)
{
    return arr < end ? *arr + sum(arr + 1, end) : 0;
}

int main()

{
    int n, m;
    scanf("%d%d", &n, &m);
    if (n < 1 && m < 1)
    {
        printf("n is wrong: %d\n", n);
        printf("m is wrong: %d", m);
    }

    if (n < 1 && m >= 1)
        printf("n is wrong: %d\n", n);
    if (m < 1 && n >= 1)
        printf("m is wrong: %d", m);

    if (n >= 1 && m >= 1)
    {
        int arr[n][m];
        int k = 1;
        for (int i = 0; i < n; i++)
            for (int j = 0; j < m; j++)
            {
                arr[i][j] = k;
                k++;
            }
        printf("sum = %d\n", sum(*arr, *arr + n * m));
    }
    return 0;
}