Problem:
Score : 100 points

Problem Statement

Joisino wants to evaluate the formula "A op B".
Here, A and B are integers, and the binary operator op is either + or -.
Your task is to evaluate the formula instead of her.

Constraints

1≦A,B≦10^9

op is either + or -.

Input

The input is given from Standard Input in the following format:

A op B

Output

Evaluate the formula and print the result.

Sample Input 1

1 + 2

Sample Output 1

3

Since 1 + 2 = 3, the output should be 3.

Sample Input 2

5 - 7

Sample Output 2

-2

Solution in C (GCC 9.2.1) (judge verdict: Runtime Error)

#include<stdio.h>

int main(){
   int n;
   scanf("%d", &n);
   int a[1<<19]={0}, count_a[1<<19]={0};
   for(int i=0; i<n; i++){
       scanf("%d", &a[i]);
       count_a[a[i]]++;
    }
    long int p = 1;
    for(int i=0; i<n; i++){
      if(2*i+1-n%2<n){ 
          if(count_a[2*i+1-n%2]>=3||count_a[2*i+2-n%2]>=1){
              count_a[2*i+1-n%2] = 0;
          }
          p *= count_a[2*i+1-n%2]%(1000000000+7);
       }
    }
    if(count_a[0]>=2){
        puts("0");
        return 0;
    }
    else if(p == (1<<((n-n%2)/2))%(1000000000+7)){
        printf("%ld\n", p);
        return 0;
    }
    else {
        puts("0");
        return 0;
    }
   


}