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<string>
#include<vector>
#include<algorithm>
#include<math.h>
using namespace std;
typedef pair<int, int>P;

int main() {
	char s;
	cin >> s;
	if (s == 'A') {
		cout << 'T' << endl;
	}
	else if (s == 'C') {
		cout << 'G' << endl;
	}
	else if (s == 'G') {
		cout << 'C' << endl;
	}
	else if (s == 'T') {
		cout << 'A' << endl;
	}
	return 0;
}