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: Wrong Answer)

#include <iostream>
#include <vector>

using namespace std;

int main() {
    char b;
    cin >> b;

    vector<pair<char, char> > bases = {
                                    make_pair('A', 'T'), 
                                    make_pair('C', 'G'), 
                                    make_pair('G', 'C'), 
                                    make_pair('T', 'A')
                            };
    for (int i = 0; i < 4; i++) {
        if (b == bases[i].first) cout << bases[i].second << endl;
        break;
    }
    
    return 0;
}