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)

S = input()
A = ""
for s in S:
    if s == "A":
        A += "T"
    elif s == "T":
        A += "A"
    elif s == "C":
        A += "G"
    else:
        A += "C"
print(A)