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 Python (3.4.3) (judge verdict: Wrong Answer)

s = input()
 
ans = [0]
cnt = 0
for i in s:
    if (i == "A" or i == "C" or i == "G" or i == "T"):
        cnt+=1
    else:
        if (cnt > 0):
            ans.append(cnt)
            cnt = 0
ans.append(cnt)
print(max(ans))