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 (Clang 10.0.0) (judge verdict: Wrong Answer)

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

int main(void)
{
  long  int n,i;
  long long int *a;
  scanf("%ld",&n);
  
  a=calloc(n,sizeof(long long int));
    
  for(i=0;i<n;i++)
  {
    scanf("%lld",&a[i]);
    if(a[i]>1000000000000000000)
    {
      printf("-1");
      return 0;
    }
    if(a[i]==0)
    {
      printf("0");
      return 0;
    }
  }
  
  long long int s=1;
  for(i=0;i<n;i++)
  {
    s=s*a[i];
    
  }
  if(s>1000000000000000000)
    {
      	printf("-1");
    	return 0;
    }

  
  	printf("%lld",s);
  
  return 0;
}