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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <iostream>
#include <cstring>
#include <cmath>
#include <vector>
#include <algorithm>
#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <set>
#include <map>

using namespace std;

int main()
{
    map<char,char> b;
    b['A'] = 'T';
    b['T'] = 'A';
    b['G'] = 'C';
    b['C'] = 'G';
    
    char s;
    cin >> s;
    cout << b[s] << endl;
}