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 <bits/stdc++.h>
using namespace std;

int main(){
    string b;
    cin >> b ;
    if (b == "A"){
        cout << "T" <<endl;
    }
    if (b == "T"){
        cout << "A" <<endl;
        
}
    if (b == "G"){
        cout << "C" << endl;
    }
    if (b == "C"){
        cout << "G" << endl;
    }
}