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 <algorithm>
#include <cstdint>
#include <iostream>
#include <numeric>
#include <vector>

using namespace std;
using myui = uint64_t;

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    {
        char c;
        cin >> c;
        switch(c) {
            case 'A':
                cout << 'T' << endl;
                break;
            case 'C':
                cout << 'G' << endl;
                break;
            case 'G':
                cout << 'C' << endl;
                break;
            case 'T':
                cout << 'A' << endl;
                break;
        }
    }

    return 0;
}