A = float (input())
B = float (input())
C = str (input())
if C =='+':
    print(A+B)
elif C =='-':
    print(A-B)
elif C =='*':
    print(A*B)
elif C =='/' and B==0:
    print("Деление на 0!")
elif C =='/' and B!=0:
    print(A/B)
elif C =='mod' and B==0:
    print('Деление на 0!')
elif C =='mod' and B!=0:
    print(A%B)
elif C =='pow':
    print(A**B)
elif C =='div' and B==0:
    print('Деление на 0!')
elif C=='div' and B!=0:
    print(A//B)