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):
moji = str(input())
correct = ["A","C","G","T"]
ind = correct.index(moji) + 1
print(correct[ind*-1])

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):
s = input()

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

Solution (Python):
def f(c):
  if c == "A":
    return "T"
  elif c == "T":
    return "A"
  elif c == "C":
    return "G"
  else:
    return "C"

print(f(input()))

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

Solution (Python):
d = dict()
d["A"] = "T"
d["T"] = "A"
d["C"] = "G"
d["G"] = "C"
S = input()
print(d[S])

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


if __name__ == '__main__':
    main()

Solution (Python):
a = ['A','C','G','T']
b = ['T','G','C','A']
asn = ''
s = str(input())
for i in range(4):
    if s == a[i]:
        print(b[i])

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):



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":
  print("T")
elif s == "T":
  print("A")
elif s == "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):
print(input().replace("A","a").replace("T","A").replace("a","T").replace("G","g").replace("C","G").replace("g","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):
n=input()
c=["A","T","G","C"]
a=["T","A","C","G"]
for i in range(4):
    if n==c[i]:
        print(a[i])
        break

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

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

Solution (Python):
char = input()

answer = ''
if char == 'A':
    answer = 'T'
elif char == 'C':
    answer = 'G'
elif char == 'G':
    answer = 'C'
else:
    answer = 'A'

print(answer)

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):



import sys

b = input()

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

print(d[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()

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

main()

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 == 'C':
    print('G')
elif b == 'G':
    print('C')

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

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

Solution (Python):
b = input()

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

print(dic[b])

Solution (Python):
print("ATCG"["TAGC".index(input())])

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

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

print(dh[b])

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

Solution (Python):
b = input()

s0 = ['A', 'T', 'C', 'G']
s1 = ['T', 'A', 'G', 'C']

for i, s in enumerate(s0):
    if s == b:
        print(s1[i])
        break

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

n=str(input())
if n=='A':
    print('T')
elif n=='T':
    print('A')
elif n=='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')

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()

if b == 'A':
    print('T')
elif b == 'C':
    print('G')
elif b == 'G':
    print('C')
else:
    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 =="C":
    print("G")
elif 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):
d = {'A': 'T', 'T': 'A', 'C': 'G', 'G': 'C'}
print(d[input()])

Solution (Python):
L = ["A","T","A","G","C","G"]
print(L[L.index(input())+1])

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):
DNA_b = input()

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

Solution (Python):

b = input()


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

if 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()

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


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

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

Solution (Python):
b = input()

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

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

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

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

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


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 == "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()

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')

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

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

if b == ('G'):
    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')

else:
    print('入力に誤りがあります。A,C,G,Tのいずれかを入力して下さい。')

Solution (Python):
print("ATCG"["TAGC".find(input())])

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

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

Solution (Python):
b = input()

if b == ('A'):
    print('T')
elif b == ('C'):
    print('G')
elif b == ('G'):
    print('C')
elif b == ('T'):
    print('A')
else:
    print('入力に誤りがあります。A,C,G,Tのいずれかを入力してください。')

Solution (Python):
b = input()

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

Solution (Python):
b = input()

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

print(answer)

Solution (Python):
b=input()

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

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 = 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('ACGT'['TGCA'.index(input())])

Solution (Python):
data = input()

if data == 'A':
    print('T')
elif data == 'T':
    print('A')
elif data == 'C':
    print('G')
elif data == '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")
else:
    print("You made a mistake.")

Solution (Python):

caracter = input()

if caracter == 'A':
    print('T')

if caracter == 'T':
    print('A')

if caracter == 'C':
    print('G')

if caracter == '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':
    answer = 'T'
elif b == 'T':
    answer = 'A'
elif b == 'C':
    answer = 'G'
elif b == 'G':
    answer = 'C'
else:
    answer = '入力間違い【A】【T】【C】【G】を入力'

print(answer)

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 = str(input())

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

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

elif b == 'G':
    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):
b=str(input())
E={"A":"T","T":"A","C":"G","G":"C"}
print(E[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):
b = input()

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

elif b == 'T':
    print('A')

elif b == 'C':
    print('G')

elif b == 'G':
    print('C')

else:
    print('error!')

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

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):
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):
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()



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



elif b == 'G':
    print('C')
elif b == 'C':
    print('G')

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")

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()

print({'A':'T', 'T':'A', 'G':'C', 'C':'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):
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 == '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 == "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):
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 == 'G':
    print('C')
elif b == 'T':
     print('A')
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()
dic = {'A':'T','G':'C','T':'A','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):
base  = {'A':'T', 'C':'G', 'G':'C', 'T':'A'}
print(base.get(input()))

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):
b = input()

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

elif b == 'T':
    print('A')

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

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().upper()

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 == '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 = 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 == "C":
    print("G")
else:
    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()

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

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

Solution (Python):



b = input()


if b == 'A':
    answer = 'T'
elif b == 'T':
    answer = 'A'
elif b == 'C':
    answer = 'G'
elif b == 'G':
    answer = 'C'
else:
    answer = '入力値は　A, C, G, T　のいずれかを選択'


print(answer)

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

Solution (Python):
S = input()
print_list = ['A', 'C', 'G', 'T']
value = print_list.index(S)
print(print_list[3-value])

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()


output_srt = 'None'
if b == 'A':
    output_srt = 'T'
elif b == 'C':
    output_srt = 'G'
elif b == 'G':
    output_srt = 'C'
elif b == 'T':
    output_srt = 'A'

print(output_srt)

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()
bp_dict = {'A': 'T', 'C': 'G'}
if b == 'A':
    print('T')
if b == 'T':
    print('A')
if b == 'C':
    print('G')
if 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 = str(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):
b = input()

if b == 'A':
    print('T')
elif b == 'T':
    print('A')
elif b == 'C':
    print('G')
elif b == 'G':
    print('C')
else:
    print('A,T,C,G のうちどれかを入力してください。')

Solution (Python):


b = input() 

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

print(pair_base)

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 = str(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('')


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

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

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

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

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

Solution (Python):

base = input()
"AとTのペアで出力、CとGのペアで出力"
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')
elif b == 'T':
    print('A')

if b == 'C':
    print('G')
elif b == 'G':
    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):
b=input()



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


print(a[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 = "ATAGCG"
print(b[1+b.index(input())])

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

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

Solution (Python):





base = input()



if base == 'A':
    
    answer = 'T'
elif base == 'T':
    
    answer = 'A'
elif base == 'G':
    
    answer = 'C'
elif base == 'C':
    
    answer = 'G'


print(answer)

Solution (Python):





base = input()



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

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

Solution (Python):
base = input('')

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

Solution (Python):
import sys

read = sys.stdin.read
readline = sys.stdin.readline
readlines = sys.stdin.readlines
sys.setrecursionlimit(10 ** 9)
INF = 1 << 60
MOD = 1000000007


def main():
    b = readline().strip()
    
    print(b.translate(str.maketrans('ACGT','TGCA')))
    
    return


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

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

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

Solution (Python):
b=input()
L=['A','C','G','T']
c=L.index(b)
print(L[3-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()
dic = {"A":"T", "T":"A", "C":"G", "G":"C"}
print(dic[b])

Solution (Python):
b=input()
IN=['A','C','G','T']
OUT=['T','G','C','A']

for i in range(4):
    if b==IN[i]:
        print(OUT[i])
        break

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):
def readinput():
    b=input()
    return b

def main(b):
    dic={'A':'T', 'C':'G', 'T':'A', 'G':'C'}
    return dic[b]

if __name__=='__main__':
    b=readinput()
    ans=main(b)
    print(ans)

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=='A':
  print('T')
elif b=='T':
  print('A')
elif b=='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):








s = input()

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

print(h[s])

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

Solution (Python):
b = input()
res = ''

for s in b:
    if s == 'A':
        res += 'T'
    elif s == 'T':
        res += 'A'
    elif s == 'C':
        res += 'G'
    elif s == 'G':
        res += 'C'

print(res)

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

Solution (Python):

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

if __name__ == "__main__":
    main()

Solution (Python):
dict={"A":"T","T":"A","G":"C","C":"G"}
print(dict[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):
a = {"A":"T", "T":"A", "C":"G", "G": "C"}
print(a[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):
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):
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='ATACGC'
print(b[1+b.index(input())])

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):
import sys


stdin = sys.stdin
def ns(): return stdin.readline().rstrip()
def ni(): return int(stdin.readline().rstrip())
def nm(): return map(int, stdin.readline().split())
def nl(): return list(map(int, stdin.readline().split()))


def main():
    D = list(input())
    dic = {'A': 'T', 'C': 'G', 'G': 'C', 'T': 'A'}
    ans = []
    for d in D:
        ans.append(dic[d])
    print(''.join(ans))


if __name__ == '__main__':
    main()

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()

print(b.translate(str.maketrans({'A': 'T', 'C': 'G', 'T': 'A', 'G': 'C'})))

Solution (Python):
import sys
def S(): return sys.stdin.readline().rstrip()

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