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: Wrong Answer)

#include<stdio.h>
int main(){
  char S[10];
  scanf("%s",S);
  int i;
  int cnt=0;
  int ans=0;
  for(i=0;S[i]!='\0';i++){
	if(S[i]=='A'||S[i]=='T'||S[i]=='C'||S[i]=='G') {
      cnt++;
    }
    else if(cnt>ans){
      ans=cnt;
      cnt=0;
    }
  }
  
  if(cnt>ans) ans=cnt;
  
  printf("%d",ans);
  return 0;
}