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 <stdio.h>
#include <vector>
#include <iostream>
#include <queue>
#include <bits/stdc++.h>
 
#define rep(i,n) for (int i=0;i<(n);++i)
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<double> vd;
typedef pair<int, int> pi;


int main() {
  char b;
  cin >> b;
  map<char, char> mp;
  mp['A'] = 'T';
  mp['T'] = 'A';
  mp['C'] = 'G';
  mp['G'] = 'C';
  cout << mp[b] << endl;
  return 0;
}