#include <stdio.h>
#include <stdlib.h>

int main()
{
        int num = 9;
        int i, sum; i = 1, sum = 0;
        while (i < 2 * num) {
                sum = sum + i * i;
                ++i;
        }
        printf("sum: %d\n", sum);
        fflush(stdout);
        return 0;
}