#include <iostream>
using namespace std;
int main() {
double a, b;
char op;
cin >> a >> op >> b;
if (op == '+')
cout << a + b;
else if (op == '-')
cout << a - b;
else if (op == '*')
cout << a * b;
else if (op == '/')
cout << a / b;
else
cout << "error";
return 0;
}
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