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 (Python):
s = input()

if s == "A":
  print("T")
elif s == "T":
  print("A")
elif s == "G":
  print("C")
else:
  print("G")

Solution (Python):
s = str(input())

if s=="A":
  print("T")
elif s=="T":
  print("A")
elif s=="C":
  print("G")
else:
  print("C")

Solution (Python):
star = input()

if star == "A":
    print("T")
elif star == "C":
    print("G")
elif star == "T":
    print("A")
elif  star == "G":
    print("C")

Solution (Python):
b = input()
if b == 'A':
    print('T')
elif b == 'T':
    print('A')
elif b == 'C':
    print('G')
else :
    print('C')

Solution (Python):
d={"A":"T","C":"G","G":"C","T":"A"}
print(d[input()])

Solution (Python):
b = input()
o = ('A' if b == 'T' else
     'C' if b == 'G' else
     'G' if b == 'C' else
     'T')
print(o)

Solution (Python):
print({'A':'T','T':'A','C':'G','G':'C'}[input()])

Solution (Python):
b=input()
if b== 'A' :
	print( 'T')
elif b == 'C' :
	print( 'G')
elif b == 'G':
	print( 'C')
else:
  print('A')

Solution (Python):
b = input()
if b == 'A':
    print('T')
elif b == 'T':
    print('A')
elif b == 'C':
    print('G')
elif b == 'G':
    print('C')

Solution (Python):
b = str(input())

if b == "A":
    print("T")

if b == "T":
    print("A")

if b == "C":
    print("G")

if b == "G":
    print("C")

Solution (Python):
b = input()

if b == 'A':
    print('T')
elif b == 'T':
    print('A')
elif b == 'C':
    print('G')
else:
    print('C')

Solution (Python):
b = input()
if b == 'A':
  print('T')
elif b == 'T':
  print('A')
elif b == 'G':
  print('C')
elif b == 'C':
  print('G')

Solution (Python):
b = input()

if b == 'A':
    print('T')
elif b == 'T':
    print('A')
elif b == 'G':
    print('C')
elif b == 'C':
    print('G')

Solution (Python):
b = input()
if b == "A":
  print("T")
elif b == "T":
  print("A")
elif b == "C":
  print("G")
elif b == "G":
  print("C")

Solution (Python):
ans ={"A":"T","T":"A","G":"C","C":"G"}
print(ans[input()])

Solution (Python):
from collections import defaultdict, Counter
from itertools import product, groupby, count, permutations, combinations
from math import pi, sqrt
from collections import deque
from bisect import bisect, bisect_left, bisect_right
from string import ascii_lowercase
from functools import lru_cache
import sys
sys.setrecursionlimit(10000)
INF = float("inf")
YES, Yes, yes, NO, No, no = "YES", "Yes", "yes", "NO", "No", "no"
dy4, dx4 = [0, 1, 0, -1], [1, 0, -1, 0]
dy8, dx8 = [0, -1, 0, 1, 1, -1, -1, 1], [1, 0, -1, 0, 1, 1, -1, -1]


def inside(y, x, H, W):
    return 0 <= y < H and 0 <= x < W


def ceil(a, b):
    return (a + b - 1) // b



def gcd(a, b):
    if b == 0:
        return a
    return gcd(b, a % b)



def lcm(a, b):
    g = gcd(a, b)
    return a / g * b


def main():
    b = input()
    m = {"A": "T", "T": "A", "C": "G", "G": "C"}

    print(m[b])


if __name__ == '__main__':
    main()

Solution (Python):
b=input()
if b=="A":
    print("T")
elif b=="T":
    print("A")
elif b=="G":
    print("C")
else:
    print("G")

Solution (Python):
l=input()
print("A" if l=="T" else "T" if l=="A" else "G" if l=="C" else "C")

Solution (Python):
base = ["A", "C", "G", "T"]
twin = ["T", "G", "C", "A"]

a = input()

print(twin[base.index(a)])

Solution (Python):
b = input()
c = {'A':'T', 'T':'A', 'G':'C', 'C':'G'}
print(c[b])

Solution (Python):
base = input()
if base == 'A':
    print('T')
elif base == 'T':
    print('A')
elif base == 'C':
    print('G')
else:
    print('C')

Solution (Python):
b = input()
if b == 'A':
    print('T')
if b == 'T':
    print('A')
if b == 'G':
    print('C')
if b == 'C':
    print('G')

Solution (Python):
b = input()

if b == "A":
    print("T")
elif b == "T":
    print("A")
elif b == "G":
    print("C")
elif b == "C":
    print("G")

Solution (Python):

mo_ji = input()

if mo_ji == "A":
    mo_ji = "T"
elif mo_ji == "C":
    mo_ji = "G"
elif mo_ji == "G":
    mo_ji = "C"
elif mo_ji == "T":
    mo_ji = "A"

print(mo_ji)

Solution (Python):
b = input()

if b == 'A':
  print('T')
elif b == 'T':
  print('A')
elif b == 'C':
  print('G')
else:
  print('C')

Solution (Python):
b = input()
dict = {'A':'T','T':'A','C':'G','G':'C'}
print(dict[b])

Solution (Python):
b = input()
dic = {"A":"T", "C":"G", "G":"C", "T":"A"}
print(dic[b])

Solution (Python):
a = input()

if a == 'A':
	print('T')
if a == 'T':
	print('A')
if a == 'G':
	print('C')
if a == 'C':
	print('G')

Solution (Python):
s = input()
if s == "A" :
  print("T")
elif s=="T" :
  print("A")
elif s=="C" :
  print("G")
else :
  print("C")

Solution (Python):
def main():
    base = input()

    if base == 'A':
        print('T')
    elif base == 'T':
        print('A')
    elif base == 'G':
        print('C')
    elif base == 'C':
        print('G')


if __name__ == "__main__":
    main()

Solution (Python):
b = input().rstrip()
if b == 'A':
  print('T')
elif b == 'T':
  print('A')
elif b == 'C':
  print('G')
elif b == 'G':
  print('C')

Solution (Python):
x = input()
print([[["C","G"][x=="C"],"T"][x=="A"],"A"][x=="T"])

Solution (Python):
k = input()
m = (k=="A" and "T") or (k=="T" and "A") or (k=="C" and "G") or (k=="G" and "C")
print(m)

Solution (Python):

b=str(input())

if b == "A":
    print("T")
elif b == "T":
    print("A")
elif b == "C":
    print("G")
elif b == "G":
    print("C")

Solution (Python):
print({'A':'T','T':'A','C':'G','G':'C'}[input()])

Solution (Python):


b=input()

if b=="A":
    print("T")
elif b=="T":
    print("A")
elif b=="C":
    print("G")
else:
    print("C")

Solution (Python):
b=input()
if b=="A":
    print("T")
elif b=="T":
    print("A")
elif b=="C":
    print("G")
else:
    print("C")

Solution (Python):
def sub():
    b = input()
    if b == "A":
        print("T")
    elif b == "T":
        print("A")
    elif b == "C":
        print("G")
    else:
        print("C")

sub()

Solution (Python):
b = input()

if b == 'A':
    print('T')
if b == 'T':
    print('A')
if b == 'C':
    print('G')
if b == 'G':
    print('C')

Solution (Python):
str = input()
if str == "A":
  print("T")
elif str == "T":
  print("A")
elif str == "G":
  print("C")
elif str == "C":
  print("G")

Solution (Python):
print(['A','T','C','G'][['T','A','G','C'].index(input())])

Solution (Python):

b = input()
dict = {"A":"T","C":"G","T":"A","G":"C"}
print(dict[b])

Solution (Python):
a=input()
if a=='A':
    print('T')
elif a=='T':
    print('A')
elif a=='C':
    print('G')
else:
    print('C')

Solution (Python):
b = input()

if b == 'A':
    print('T')
elif b == 'T':
    print('A')
elif b == 'C':
    print('G')
else:
    print('C')

Solution (Python):
a = input()
if a == "A":
  print("T")
if a == "T":
  print("A")
if a == "G":
  print("C")
if a == "C":
  print("G")

Solution (Python):
dic = {"A":"T","C":"G","G":"C","T":"A"}
print(dic[input()])

Solution (Python):
b = input()
if b == "A":
    print("T")
if b == "T":
    print("A")
if b == "C":
    print("G")
if b == "G":
    print("C")

Solution (Python):
b = input()

if b == "A":
  print("T")
elif b == "T":
  print("A")
elif b == "C":
  print("G")
elif b == "G":
  print("C")

Solution (Python):
m = {'A':'T', 'T':'A', 'C':'G', 'G':'C'}

print(m[input()])

Solution (Python):
b=input()
if b=="A":
  print("T")
elif b=="C":
  print("G")
elif b=="T":
  print("A")
elif b=="G":
  print("C")

Solution (Python):
b = input()
if b == "A":
    print("T")
elif b == "C":
    print("G")
elif b == "G":
    print("C")
else:
    print("A")

Solution (Python):
b = input()

if b == 'A':
    print('T')
elif b == 'C':
    print('G')
elif b == 'G':
    print('C')
elif b == 'T':
    print('A')

Solution (Python):
b = input()

if b == "A":
    print("T")
elif b == "T":
    print("A")
elif b == "G":
    print("C")
else:
    print("G")

Solution (Python):



a = input()

if(a == "A"):
    print("T")
elif( a == "T"):
    print("A")
elif( a == "G"):
    print("C")
else:
    print("G")

Solution (Python):
b = str(input())

if b == "A" :
    print("T")
elif b == "T" :
    print("A")
elif b == "C" :
    print("G")
else :
    print("C")

Solution (Python):
b = input()
if b == "A":
    print("T")
elif b == "C":
    print("G")
elif b == "G":
    print("C")
elif b == "T":
    print("A")

Solution (Python):
base_letter = input()

matching_bases = {
    'A': 'T',
    'C': 'G',
    'T': 'A',
    'G': 'C'
}

if base_letter in matching_bases:
    print(matching_bases[base_letter])

Solution (Python):
p='ACGTTGCA'
print(p[p.find(input())+4])

Solution (Python):
a = input()
if a == 'A':
    print('T')
elif a == 'T':
    print('A')
elif a == 'G':
    print('C')
elif a == 'C':
    print('G')

Solution (Python):
b = input()

if (b=="T"):
  print("A")
elif(b=="A"):
  print("T")
elif(b=="C"):
  print("G")
else:
  print("C")

Solution (Python):
b = input()
if b=='A':
	print('T')
if b=='T':
	print('A')
if b=='G':
	print('C')
if b=='C':
	print('G')

Solution (Python):
b = input()
if b == "A":
    print("T")
elif b == "T":
    print("A")
elif b == "C":
    print("G")
else:
    print("C")

Solution (Python):
import sys

b=input()
if(b=='A'):
    ans='T'
elif(b=='T'):
    ans='A'
elif(b=='C'):
    ans='G'
elif(b=='G'):
    ans='C'

print(ans)

Solution (Python):
b = input()

if b == 'A':
    print('T')
elif b == 'T':
    print('A')
elif b == 'C':
    print('G')
elif b == 'G':
    print('C')
else:
    pass

Solution (Python):
x=input()
if x=='A':
  print('T')
elif x=='T':
  print('A')
elif x=='C':
  print('G')
elif x=='G':
  print('C')
else:
  pass

Solution (Python):
s = input()

if (s == 'A'):
    out = 'T'
elif (s == 'T'):
    out = 'A'
elif (s == 'C'):
    out = 'G'
else:
    out = 'C'

print(out)

Solution (Python):
b = input()
if b == "A":
    ans = "T"
if b == "C":
    ans = "G"
if b == "G":
    ans = "C"
if b == "T":
    ans = "A"
print(ans)

Solution (Python):

import sys


def solve(b: str):
    if b == "A":
        print("T")
    if b == "T":
        print("A")
    if b == "C":
        print("G")
    if b == "G":
        print("C")



def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    b = next(tokens)  
    solve(b)

if __name__ == '__main__':
    main()

Solution (Python):
b = input()
if b == "A":
  print("T")
elif b == "T":
  print("A")
elif b == "C":
  print("G")
else:
  print("C")

Solution (Python):
b = input()
if b == "A":
    print("T")
elif b == "T":
    print("A")
elif b == "G":
    print("C")
else:
    print("G")

Solution (Python):

b = input()

if b is 'A':
    print('T')
elif b is 'T':
    print('A')
elif b is 'C':
    print('G')
elif b is 'G':
    print('C')

Solution (Python):
b = input()

if b == 'A':
  print('T')
elif b == 'T':
  print('A')
elif b == 'C':
  print('G')
elif b == 'G':
  print('C')

Solution (Python):
b = input()

if b == "A":
    print("T")
elif b == "T":
    print("A")
elif b == "C":
    print("G")
else:
    print("C")

Solution (Python):
d = {'A':'T','T':'A','C':'G','G':'C'}
b = input()
print(d[b])

Solution (Python):
b = input()
if b == "A":
    print("T")
if b == "T":
    print("A")
if b == "C":
    print("G")
if b == "G":
    print("C")

Solution (Python):
b = input()

if b == "A":
  print("T")
elif b == "T":
  print("A")
elif b == "C":
  print("G")
else:
  print("C")

Solution (Python):
s = input()
if s == "A" : s = "T"
elif s == "T" : s = "A"
elif s == "C" : s = "G"
else : s = "C"
print(s)

Solution (Python):
b=input()
if b=="A":
  print("T")
elif b=="T":
  print("A")
elif b=="C":
  print("G")
elif b=="G":
  print("C")

Solution (Python):
import sys


def input():
    return sys.stdin.readline()[:-1]








a = str(input())
dic = {"A": "T", "T": "A", "C": "G", "G": "C"}
print(dic[a])

Solution (Python):
a = input()
if a == "A":
    print("T")
if a == "T":
    print("A")
if a == "G":
    print("C")
if a == "C":
    print("G")

Solution (Python):
b = str(input())

if b == "A":
  print("T")
elif b == "T":
  print("A")
elif b == "G":
  print("C")
else:
  print("G")

Solution (Python):
def m():
    s = input()
    if s == 'A':
        return 'T'
    if s == 'T':
        return 'A'
    if s == 'G':
        return 'C'
    if s == 'C':
        return 'G'
print(m())

Solution (Python):
b=input()
pair={"A":"T","C":"G","T":"A","G":"C"}
print(pair[b])

Solution (Python):
x=input()

if x=="A":
  print("T")
elif x=="T":
  print("A")
elif x=="C":
  print("G")
else:
  print("C")

Solution (Python):
b = input()
AT = ["A", "T"]
CG = ["C", "G"]
if b in AT:
    if b == AT[0]:
        print(AT[1])
    else:
        print(AT[0])
elif b in CG:
    if b == CG[0]:
        print(CG[1])
    else:
        print(CG[0])

Solution (Python):
print({
    'A': 'T',
    'C': 'G',
    'G': 'C',
    'T': 'A',
}[input().strip()])

Solution (Python):
def main():
    n = input()
    if n =='A':
        print('T')
    elif n =='T':
        print('A')
    elif n =='C':
        print('G')
    else:
        print('C')

if __name__ == '__main__':
    main()

Solution (Python):
print({'A': 'T', 'T': 'A', 'C': 'G', 'G': 'C'}[input()])

Solution (Python):
b = input()
if b == 'A':
  print('T')
elif b == 'T':
  print('A')
elif b == 'C':
  print('G')
else:
  print('C')

Solution (Python):
b = input()

if b == "A":
    print("T")
elif b == "T":
    print("A")
elif b == "C":
    print("G")
else:
    print("C")

Solution (Python):
l = str.maketrans('ACGT', 'TGCA')
b = input().translate(l)
print(b)

Solution (Python):

"""
Created on Mon May 13 15:09:45 2019

@author: avina
"""

d = {'A' : 'T', 'C': 'G', 'G':'C', 'T':'A'}
g = input().strip()
print(d[g])

Solution (Python):
b = input().split()[0]
m = dict()
m["A"] = "T"
m["T"] = "A"
m["C"] = "G"
m["G"] = "C"
print(m[b])

Solution (Python):
b = input()

if b =="A":
  ret = "T"
elif b == "T": 
  ret = "A"
elif b == "G": 
  ret = "C"
elif b == "C": 
  ret = "G"
print(ret)

Solution (Python):
b=input()
if b=='A':
  print('T')
elif b=='T':
  print('A')
elif b=='G':
  print('C')
else:
  print('G')

Solution (Python):
b=input()
if b=="A":
  print("T")
if b=="T":
  print("A")
if b=="G":
  print("C")
if b=="C":
  print("G")

Solution (Python):
b = input()

if b == 'A':
    print('T')
elif b == 'T':
    print('A')
elif b == 'C':
    print('G')
elif b == 'G':
    print('C')

Solution (Python):
from sys import stdin
b = stdin.readline().rstrip()

if b == 'A':
    print('T')
elif b == 'T':
    print('A')
elif b == 'C':
    print('G')
elif b == 'G':
    print('C')

Solution (Python):
s = input()
if s == 'A':
    print('T')
elif s == 'T':
    print('A')
elif s == 'C':
    print('G')
else:
    print('C')

Solution (Python):
b = input()
if b == "T":
    print("A")
elif b == "A":
    print("T")
elif b == "G":
    print("C")
else:
    print("G")

Solution (Python):
N=input()
if N=="A":
    print("T")
elif N=="T":
    print("A")
elif N=="C":
    print("G")
elif N=="G":
    print("C")

Solution (Python):


b = input()

ans = {"A":"T", "T":"A", "C":"G", "G":"C"}
print(ans[b])

Solution (Python):
abc = input()

if abc == 'A':
    print("T")
elif  abc == 'T':
    print("A")
elif abc == 'C':
    print("G")
elif  abc == 'G':
    print("C")

Solution (Python):
b = input()

if b == 'A':
    print('T')
elif b == 'T':
    print('A')
elif b == 'G':
    print('C')
else:
    print('G')

Solution (Python):
l = ['A', 'C', 'T', 'G']
b = input()
for i in range(4):
    if l[i] == b:
        print(l[(i+2)%4])
        break

Solution (Python):
b = input()
if b == "A":
	print("T")
elif b == "T":
	print("A")
elif b == "C":
	print("G")
elif b == "G":
	print("C")

Solution (Python):
import sys

b = input()

if b == 'A':
    print("T")
    sys.exit()
if b == 'T':
    print("A")
    sys.exit()
if b == 'C':
    print("G")
    sys.exit()
print("C")

Solution (Python):
b = input()
ans = {"A": "T", "T": "A", "C": "G", "G":"C"}

print(ans[b])

Solution (Python):
pat = str.maketrans("ATCG", "TAGC")
print(input().translate(pat))

Solution (Python):
s =  input()

if s == 'C':
    print('G')
elif s== 'G':
    print('C')
elif s=='A':
    print('T')
else:
    print('A')

Solution (Python):
b=input()
if b=='A':
    print('T')
elif b=='T':
    print('A')
elif b=='G':
    print('C')
elif b=='C':
    print('G')

Solution (Python):
b = input()

if b == 'A':
    print('T')
if b == 'T':
    print('A')
if b == 'C':
    print('G')
if b == 'G':
    print('C')

Solution (Python):
p = {
    'A': 'T',
    'T': 'A',
    'C': 'G',
    'G': 'C'
}

print(p[input()])

Solution (Python):
enki = input()
if enki == 'A':
    print('T')
elif enki == 'T':
    print('A')
elif enki == 'G':
    print('C')
else:
    print('G')

Solution (Python):
b = str(input())

if b == 'A' :
	print('T')
elif b == 'T':
	print('A')
elif b == 'C':
	print('G')
elif b == 'G':
	print('C')

Solution (Python):
a=input()

if a=="G":
  print("C")
elif a=="C":
  print("G")
elif a=="T":
  print("A")
elif a=="A":
  print("T")

Solution (Python):
b = input()
if b == "A":
 print("T")
elif b == "T":
 print("A")
elif b == "C":
 print("G")
elif b == "G":
 print("C")

Solution (Python):
b=input()
if b=='A':
    print('T')
elif b=='T':
    print('A')
elif b=='G':
    print('C')
else:
    print('G')

Solution (Python):
b=input()
if b == 'A':
    print('T')
elif b == 'T':
    print('A')
elif b == 'C':
    print('G')
else:
    print('C')

Solution (Python):
b = input()

g = {
	"A": "T",
	"C": "G",
	"G": "C",
	"T": "A"
}

print(g[b])

Solution (Python):
b = input()

if b == 'A':
    print('T')
elif b == 'T':
    print('A')
elif b == 'C':
    print('G')
elif b == 'G':
    print('C')

Solution (Python):
BASE_PAIRS = [['A', 'T'], ['C', 'G']]
base_b = input()
result = ''

for i in range(len(BASE_PAIRS)):
    if base_b in BASE_PAIRS[i]:
        paired_base_index = (BASE_PAIRS[i].index(base_b)+1) % 2
        result = BASE_PAIRS[i][paired_base_index]

print(result)

Solution (Python):
b = input()

if b == 'A':
    print('T')
elif b == 'T':
    print('A')
elif b == 'C':
    print('G')
elif b == 'G':
    print('C')

Solution (Python):
b = input()
if b == "A":
    print("T")
if b == "C":
    print("G")
if b == "G":
    print("C")
if b == "T":
    print("A")

Solution (Python):
b = input()
dic = {'A':'T','C':'G','T':'A','G':'C'}
print(dic[b])

Solution (Python):
b=input()
base={"A":"T","T":"A","C":"G","G":"C"}
print(base[b])

Solution (Python):
b = input()

if b=='A':
    print("T")
elif b=='T':
    print('A')
elif b=='G':
    print('C')
elif b=='C':
    print('G')

Solution (Python):
b = input()

if b is "A":
  print("T")
elif b is "T":
  print("A")
elif b is "C":
  print("G")
else:
  print("C")

Solution (Python):
b = input()
if b == "A":
  print("T")
elif b == "T":
  print("A")
elif b == "C":
  print("G")
elif b == "G":
  print("C")

Solution (Python):
b = input()
if b == "A":
  print("T")
elif b == "T":
  print("A")
elif b == "C":
  print("G")
elif b == "G":
  print("C")

Solution (Python):
b = input()
d = {"A": "T", "C":"G", "G":"C", "T":"A"}
print(d[b])

Solution (Python):
b=input()
if b=='A':
    print('T')
elif b=='C':
    print('G')
elif b=='G':
    print('C')
else:
    print('A')

Solution (Python):
b=input()
r = ""
if b == "A":
    r = "T"
elif b == "T":
    r = "A"
elif b == "C":
    r = "G"
elif b == "G":
    r = "C"
print(r)

Solution (Python):



def main():
    b = input()
    d = {
            'A': 'T',
            'C': 'G',
            'G': 'C',
            'T': 'A'
        }
    print(d[b])


if __name__ == '__main__':
    main()

Solution (Python):
b = input()
if b == "A":
  print("T")
elif b == "T":
  print("A")
elif b == "G":
  print("C")
else:
  print("G")

Solution (Python):
b = input()

base = {"A": "T", "T": "A", "G": "C", "C": "G"}

print(base[b])

Solution (Python):
x = input()
if x == 'A':
	print('T')
elif x == 'T':
	print('A')
elif x == 'C':
	print('G')
else:
	print('C')

Solution (Python):
b = input()
dic = {'A':'T', 'C':'G'}

s = dic.get(b)
if s == None:
    if b == 'T':
        print('A')
    else:
        print('C')
else:
    print(s)

Solution (Python):

b = input()

out = ''
if b == 'A':
    out = 'T'
elif b == 'T':
    out = 'A'
elif b == 'C':
    out = 'G'
else:
    out = 'C'

print(out)

Solution (Python):
b = input()
d = {'A': 'T', 'T': 'A', 'G': 'C', 'C': 'G'}
print(d[b])

Solution (Python):
b = input()
if b == "A":
    print("T")
if b == "T":
    print("A")
if b == "G":
    print("C")
if b == "C":
    print("G")

Solution (Python):
b = input()

if b == "A":
  print("T")
elif b == "C":
  print("G")
elif b == "G":
  print("C")
else:
  print("A")

Solution (Python):
b = input()
ans = {'A': 'T', 'T': 'A', 'C': 'G', 'G': 'C'}
print(ans[b])

Solution (Python):
b = input()

if b == 'A':
    ans = 'T'
elif b == 'T':
    ans = 'A'
elif b == 'C':
    ans = 'G'
else:
    ans = 'C'
    
print(ans)

Solution (Python):
a={"A":"T","T":"A","C":"G","G":"C"}
s=input()
print(a[s])

Solution (Python):
b = input()
if b == 'A':
    print('T')
elif b == 'T':
    print('A')
elif b == 'C':
    print('G')
else:
    print('C')

Solution (Python):
import sys
input = sys.stdin.readline

s = input().strip()
m = {
    "A": "T",
    "T": "A",
    "C": "G",
    "G": "C",
}

print(m[s])

Solution (Python):
b = input()

if (b == 'A'):
    print('T')
elif (b == 'T'):
    print('A')
elif (b == 'C'):
    print('G')
else:
    print('C')

Solution (Python):
b = input()

a = {'A': 'T',
     'C': 'G',
     'G': 'C',
     'T': 'A',
    }

print(a[b])

Solution (Python):
b = input()
m = {"A":"T","T":"A","C":"G","G":"C"}
print(m[b])

Solution (Python):
b = input()
if b =="A":
  print("T")
elif b =="T":
  print("A")
elif b =="C":
  print("G")
else:
  print("C")

Solution (Python):
b = input()
if b == 'A':
  print('T')
elif b == 'T':
  print('A')
elif b == 'G':
  print('C')
else:
  print('G')

Solution (Python):


from bisect import bisect_left as binl

def intin():
    input_tuple = input().split()
    if len(input_tuple) <= 1:
        return int(input_tuple[0])
    return map(int, input_tuple)


def intina():
    return [int(i) for i in input().split()]


def intinl(count):
    return [intin() for _ in range(count)]


def lcm(x, y):
    while y != 0:
        z = x % y
        x = y
        y = z
    return x





def main():
    b = input()

    if b == 'A':
        print('T')
    if b == 'T':
        print('A')
    if b == 'C':
        print('G')
    if b == 'G':
        print('C')


if __name__ == '__main__':
    main()

Solution (Python):
b=input()

if b== "A":
  print("T")
elif b=="T":
  print("A")
elif b=="G":
  print("C")
else:
  print("G")

Solution (Python):
b=input()
if b=='A':
  print('T')
elif b=='T':
  print('A')
elif b=='C':
  print('G')
else:
  print('C')

Solution (Python):
print({"A":"T","T":"A","C":"G","G":"C"}[str(input())[:1]])

Solution (Python):
b=input()
dic={'T':'A','A':'T','G':'C','C':'G'}
print(dic[b])

Solution (Python):
b = input()
if b == 'A':
    print('T')
elif b == 'T':
    print('A')
elif b == 'C':
    print('G')
else:
    print('C')

Solution (Python):
item = input()
if item == 'A':
    result = 'T'
elif item == 'T':
    result = 'A'
elif item == 'C':
    result = 'G'
else:
    result = 'C'
print(result)

Solution (Python):
b = input()
if b == 'A':
  print('T')
elif b == 'T':
  print('A')
elif b == 'C':
  print('G')
elif b == 'G':
  print('C')
else:
  pass

Solution (Python):
b = input()

if b == 'A':
    ans = 'T'
elif b == 'C':
    ans = 'G'
elif b == 'G':
    ans = 'C'
elif b == 'T':
    ans = 'A'

print(ans)

Solution (Python):
b = input()
if b == "A":
    print("T")
elif b == "C":
    print("G")
elif b == "G":
    print("C")
elif b == "T":
    print("A")

Solution (Python):
s = input()
if s == "A":
  print("T")
if s == "T":
  print("A")
if s == "C":
  print("G")
if s == "G":
  print("C")

Solution (Python):
b= input()
print('A' if b == 'T' else 'T' if b=='A' else 'C' if b=='G' else 'G')

Solution (Python):


def main():
    b = input()
    b = b.upper()
    if b == "A":
        print("T")
    elif b == "T":
        print("A")
    elif b == "G":
        print("C")
    elif b == "C":
        print("G")

if __name__ == "__main__":
    main()

Solution (Python):
print("ACGT"["TGCA".find(input())])

Solution (Python):
b = input()
if b == 'A':
    b = 'T'
elif b == 'T':
    b = 'A'
elif b == 'G':
    b = 'C'  
else:
    b = 'G'  
 
print(b)

Solution (Python):
b = input()
if b == "A":
  print("T")
elif b == "C":
  print("G")
elif b == "G":
  print("C")
elif b == "T":
  print("A")

Solution (Python):
b = input()
ans = {'A': 'T', 'T': 'A', 'C': 'G', 'G': 'C'}
print(ans[b])

Solution (Python):
b = input()
if b == "A":
  print("T")
elif b == "T":
  print("A")
elif b == "G":
  print("C")
else:
  print("G")

Solution (Python):
dics = {"A":"T","T":"A","C":"G","G":"C"}

print(dics[str(input())])

Solution (Python):
s = input()
if s=='A':print('T')
elif s=='T':print('A')
elif s=='C':print('G')
elif s=='G':print('C')

Solution (Python):
b = str(input())

if b == str('A'):
    print("T")
    exit()
elif b == str('T'):
    print("A")
    exit()
elif b == str('G'):
    print("C")
    exit()
else:
    print("G")
    exit()

Solution (Python):

b=str(input())

if b=='T':
    print('A')
elif b=='A':
    print('T')
elif b=='G':
    print('C')
elif b=='C':
    print('G')

Solution (Python):
a = input()

if a == 'A' or a =='T':
  if a == 'A':
    print('T')
  else:
    print('A')
else:
  if a == 'G':
    print('C')
  else:
    print('G')

Solution (Python):
s = input()
ans = {'A': 'T', 'T': 'A', 'C': 'G', 'G': 'C'}
print(ans[s])

Solution (Python):
b = input()
if b == 'A':
    print('T')
if b == 'T':
    print('A')
if b == 'C':
    print('G')
if b == 'G':
    print('C')

Solution (Python):
b = input()
if b == 'A':
    print('T')
if b == 'T':
    print('A')
if b == 'C':
    print('G')
if b == 'G':
    print('C')

Solution (Python):
b = input()

b = b.replace('A','a')
b = b.replace('T','t')
b = b.replace('G','g')
b = b.replace('C','c')

b = b.replace('a','T')
b = b.replace('t','A')
b = b.replace('g','C')
b = b.replace('c','G')

print(b)

Solution (Python):
a = input()
print("T" if a == "A" else
      "A" if a == "T" else
      "G" if a == "C" else
      "C")

Solution (Python):
b=input()
e={'A':'T', 'C':'G', 'G':'C', 'T':'A'}
print(e[b])

Solution (Python):
b=input()
if b=='A':
    print('T')
elif b=='T':
    print('A')
elif b=='C':
    print('G')
else:
    print('C')

Solution (Python):
def main():
  b=input()

  if b=="A":
    print("T")
  elif b=="C":
    print("G")
  elif b=="G":
    print("C")
  elif b=="T":
    print("A")

main()

Solution (Python):
raw_data = input().split(" ")                                                    

for i in raw_data:
    if i == "A":
        print("T")

    elif i == "C":
        print("G")

    elif i == "T":
        print("A")

    elif i == "G":
        print("C")

Solution (Python):
d={"A":"T","T":"A","C":"G","G":"C"};print(d[input()])

Solution (Python):
a=input()
if a=='A':
	a='T'
elif a=='T':
	a='A'
elif a=='C':
	a='G'
else:
	a='C'
print(*a)

Solution (Python):
a=input()
if a=="A":
 print("T")
elif a=="T":
 print("A")
elif a=="C":
 print("G") 
else:
 print("C")

Solution (Python):
b=input()
if b=="A":
    print("T")
elif b=="T":
    print("A")
elif b=="G":
    print("C")
else:
    print("G")

Solution (Python):


def solve():
    b = input()

    if b == "A":
        print("T")
    elif b == "T":
        print("A")
    elif b == "C":
        print("G")
    else:
        print("C")

if __name__ == "__main__":
    solve()

Solution (Python):

a = input()
s = (("A", "T"), ("C", "G"))
d = dict(s)
d.update(dict(i[::-1] for i in s))

print(d[a])

Solution (Python):
c = str(input())
 
if c == 'A':
  print('T')
elif c == 'T':
  print('A')
elif c == 'G':
  print('C')
elif c == 'C':
  print('G')

Solution (Python):
h = {'A':'T', 'T':'A', 'G':'C', 'C':'G'}
print(h[input()])

Solution (Python):
s=input()
if s=='A':
  print('T')
elif s=='T':
  print('A')
elif s=='C':
  print('G')
else:
  print('C')

Solution (Python):
c = str(input())

if c == 'A':
  print('T')
elif c == 'T':
  print('A')
elif c == 'G':
  print('C')
elif c == 'C':
  print('G')

Solution (Python):
print('ACGT'['TGCA'.find(input())])

Solution (Python):
b=input()
if b=='A':
    print('T')
elif b=='T':
    print('A')
elif b=='C':
    print('G')
else : print('C')

Solution (Python):
s = str(input())
if s == 'A':
    print('T')
elif s == 'T':
    print('A')
elif s == 'C':
    print('G')
elif s == 'G':
    print('C')

Solution (Python):
vocab = {"A":"T","T":"A","C":"G","G":"C"}
print(vocab[input()])

Solution (Python):
x=input()

if x=="A":print("T")
if x=="T":print("A")
if x=="G":print("C")
if x=="C":print("G")

Solution (Python):
array = ["A","T","G","C"]
b = input()
if b == array[0]:
  print (array[1])
elif b == array[1]:
  print (array[0])
elif b == array[2]:
  print (array[3])
else:
  print (array[2])

Solution (Python):
b=input()
list=[("A","T"),("T","A"),("C","G"),("G","C")]
for l in list:
  if b==l[0]:
      print(l[1])
      break

Solution (Python):
b=input()
if b=="A":
  print("T")
elif b=="T":
  print("A")
elif b=="C":
  print("G")
elif b=="G":
  print("C")

Solution (Python):
b = input()
if b == "T":
  print ("A")
elif b == "A":
  print ("T")
elif b == ("G"):
  print ("C")
else:
  print ("G")

Solution (Python):
b = input()
c = {"A":"T","T":"A","C":"G","G":"C"}
print(c[b])

Solution (Python):
b = input()
if b == "A":
    print("T")
elif b== "T":
    print("A")
elif b == "C":
    print("G")
else:
    print("C")

Solution (Python):


x = input().strip()

pairs = {'A':'T', 'T':'A', 'C':'G', 'G':'C'}

print(pairs[x])

Solution (Python):
base = input()
basepair = {'A':'T', 'T':'A', 'C':'G', 'G':'C'}
print(basepair[base])

Solution (Python):
b = input()
if b=="A":
  print("T")
elif b=="C":
  print("G")
elif b=="G":
  print("C")
else:
  print("A")

Solution (Python):
b = input()
if b == 'A':
  print('T')
elif b == 'T':
  print('A')
elif b == 'G':
  print('C')
else:
  print('G')

Solution (Python):
pair = {
    "A":"T",
    "T":"A",
    "C":"G",
    "G":"C"
    }
print(pair[input()])

Solution (Python):
dic = {'A':'T', 'T':'A', 'C':'G', 'G':'C'}
S = input()
print(dic[S])

Solution (Python):
b = input()
d = {'A':'T', 'T':'A', 'C':'G', 'G':'C'}
print(d[b])

Solution (Python):
b = input()
if b in "AT":
    print("AT".replace(b, ''))
else:
    print("CG".replace(b, ''))

Solution (Python):
b = input()

char = {'A':'T','C':'G','T':'A','G':'C'}

print(char[b])

Solution (Python):
dict = {'A': 'T', 'C': 'G', 'T': 'A', 'G': 'C'}
b = input()
print(dict[b])

Solution (Python):
b = input()
     
dic = {'A':'T', 'T':'A', 'C':'G', 'G':'C'}
     
d = dic[b]
     
print(d)

Solution (Python):
W =input()

if W=="A":
    print("T")
elif W=="T":
    print("A")
elif W=="C":
    print("G")
else :
    print("C")

Solution (Python):
b = input()

dic = {'A':'T', 'T':'A', 'C':'G', 'G':'C'}

d = dic[b]

print(d)

Solution (Python):

b = input()
dict_ = {"A":"T", "C":"G", "G":"C", "T":"A"}
print(dict_[b])

Solution (Python):
b = input()
S = "ACGT"
T = "TGCA"
for i in range(4):
    if S[i] == b:
        print(T[i])
        break

Solution (Python):
b = input()

if b=='A':
    print('T')
elif b=='T':
    print('A')
elif b=='G':
    print('C')
else:
    print('G')

Solution (Python):
s = input()
if s == 'A':
    print('T')
elif s == 'T':
    print('A')
elif s == 'C':
    print('G')
elif s == 'G':
    print('C')

Solution (Python):
c = input()
if c == "A":
    print("T")
elif c == "T":
    print("A")
elif c == "G":
    print("C")
elif c == "C":
    print("G")