Problem:
Score : 100 points

Problem Statement

Compute A \times B.

Constraints

1 \leq A \leq 100

1 \leq B \leq 100

All values in input are integers.

Input

Input is given from Standard Input in the following format:

A B

Output

Print the value A \times B as an integer.

Sample Input 1

2 5

Sample Output 1

10

We have 2 \times 5 = 10.

Sample Input 2

100 100

Sample Output 2

10000

Solution in C (GCC 9.2.1) (judge verdict: Wrong Answer)

#include <stdio.h>
#include <stdbool.h>

int main()
{
    int i, n;
    bool ovf = false;
    scanf("%d", &n);
    long long int a, b = 1, res = 0;
    while (n--) {
        scanf("%lli", &a);
        if (a == 0 || b == 0) ovf = false;
        res = a * b;
        if (a == res / b) ovf = false;
        else ovf = true;
        b = res;
    }
    if (ovf == true) res = -1;
    printf("%lli\n", res);

    return 0;
}