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 (Clang 3.8.0) (judge verdict: Runtime Error)

#include <stdio.h>

int main(){

    int N, Q;
    scanf("%d %d", &N, &Q);

    int i, j, cnt=0, flag, l, r, acnum[N], accnt[N];
    char S[N+1];

    scanf("%s", S);

    for (i=0; i<N; i++){
        if (S[i] == 'A'){
            flag = 1;
        }
        if (S[i] == 'C' && flag == 1){
            acnum[cnt] = i-1;
            cnt++;
        }
        if (S[i] != 'A'){
            flag = 0;
        }
    }

    cnt = 0;
    for (i=0; i<N; i++){
        accnt[i] = cnt;
        if (i == acnum[cnt]){
            cnt++;
        }
    }

    for(i=0; i<Q; i++){
        scanf("%d %d", &l, &r);
        printf("%d\n",accnt[r-1]-accnt[l-1]);
    }

    return 0;
}