a = int(input('a: '))
b = int(input('b: '))
x = input('znak: ')
if x == "+" :
print(a+b)
elif x =="-" :
print(a-b)
elif x =="*" :
print(a*b)
elif x =="**" :
print(a**b)
elif x =="pow" :
print(a**b)
elif x =="" :
print(a**b)
elif x =="/":
if b:
print(a/b)
else:
print("Деление на 0!")