import operator
action = {
"+": operator.add,
"-": operator.sub,
"/": operator.truediv,
"*": operator.mul,
"**": operator.pow
}
# .....
b = float(input())
a = float(input())
x = input()
act= action.get(x, None)
if act:
try:
answer = act(a, b)
except ZeroDivisionError as e:
print(u"Деление на 0!")
else:
print(answer)
for i , name in enumerate(data):
print("".join([name, str(i), '.csv'])