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 (GCC 5.4.1) (judge verdict: Accepted)

//テンプレート
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <math.h>

int main(){
    char b,ans;
    scanf("%c",&b);
    switch (b) {
        case 'A':
            ans='T';
            break;
        case 'T':
            ans='A';
            break;
        case 'G':
            ans='C';
            break;
        case 'C':
            ans='G';
            break;
        default:
            break;
    }
    printf("%c\n",ans);
    return 0;
}