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: Time Limit Exceeded)

int main()
{
  unsigned long n, i, a, sum = 1;
  int flag = 1;
  scanf("%d", &n);
  unsigned long tmp = pow(10, 18);
  for (i = 0; i < n; i++)
  {
    scanf("%ld", &a);
    if (sum <= tmp && flag > 0)
    {
      sum *= a;
    } else
    {
      if (a == 0)
      {
        sum = 0;
        printf("0");
        return 0;
      } else 
      {
        flag = -1;
      }
    }
  }
  if (flag > 0)
  {
    printf("%ld", sum);
  } else 
  {
    printf("-1");
  }
}