#include <stdio.h>

int main() 
{
    int num, product;

    num = 1;
    product = 1;	/* Note - start product at 1 not 0 */
    while(num <= 7) {
        product = product *num;	/* we could also write product *= num; */
        num = num + 1;
    }

    /* Note that num will be 8 when we get to this point */
    printf("Factorial of 7 = %d\n", product);
    return 0;
}