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 Kotlin (1.0.0) (judge verdict: Runtime Error)

fun main() {
    var b: String = readLine()!!
    when (b) {
        "A" -> {
            print("T")
        }
        "T" -> {
            print("A")
        }
        "C" -> {
            print("G")
        }
        "G" -> {
            print("C")
        }
    }
}