Problem:
Score : 100 points

Problem Statement

On the Planet AtCoder, there are four types of bases: A, C, G and T. A bonds with T, and C bonds with G.

You are given a letter b as input, which is A, C, G or T. Write a program that prints the letter representing the base that bonds with the base b.

Constraints

b is one of the letters A, C, G and T.

Input

Input is given from Standard Input in the following format:

b

Output

Print the letter representing the base that bonds with the base b.

Sample Input 1

A

Sample Output 1

T

Sample Input 2

G

Sample Output 2

C

Solution in C (GCC 5.4.1) (judge verdict: Runtime Error)

#include <stdio.h>
#include<stdlib.h>
#include<math.h>
#include<string.h> 
typedef unsigned long long ll;

int num[100000]={0};
char ch[100000];
int main(){
    int N,sum=0,Q,K,i,l,r;
    scanf("%d%d",&N,&Q);
    scanf("%s",ch);
    num[0] =0;
    for(i=1;i<N;i++){
        if(*(ch+i)=='C'&&*(ch+i-1)=='A'){
            sum++;
        }
        *(num+i) = sum; 
    }
    Q = Q-1;
    for(i=Q;i>=0;i--){
        scanf("%d%d",&l,&r);
        printf("%d\n",*(num+r-1)-*(num+l-1));
    }

    return 0;
}