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: Accepted)

b = input()
#a = [int(i) for i in input().split()]
#s = [[int(j) for j in input().split()] for i in range(N)]

mp={
'A':'T',
'C':'G',
'G':'C',
'T':'A'
}
print(mp[b])