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 9.2.1) (judge verdict: Wrong Answer)

/* ex 5_4
series2 */
#include <stdio.h>
#include <string.h>

int main(void){
    char str[11];
    char count=0;
    char max=0;
    scanf("%s",str);
    for(int i=0;i<strlen(str);i++){
        if(str[i]=='A'||str[i]=='C'||str[i]=='G'||str[i]=='T'){
            count++;
        }else{
            if(count>max){
                max=count;
            }
            count=0;
        }
    }
    if(count>max){
        max=count;
    }
    printf("%d\n",max);
    return 0;
}