Time limit: 5000ms
Memory limit: 256mb

Description:
Calculate the difference of two integers.

Input:
Two integer a and b.

Output:
You should output only one line which contains an integer that equals to a minus b.

Sample input:
3 1

Sample output:
2

Hint:
The following is an example in C.
#include <stdio.h>

int main() {
  int a, b;
  scanf("%d%d", &a, &b);
  printf("%d", a - b);
}