#include <iostream>
using namespace std;

int main() {
    char op;
    double a, b;
    
    if (!(cin >> op >> a >> b)) {
        cout << "Invalid input";
        return 0;
    }
    
    switch (op) {
        case '+';
        cout << a + b;
        break;
        case '-';
        cout << a - b;
        break;
        case '*';
        cout << a * b;
        break;
        case '/';
        if (b == 0) {
            cout << "Invalid input";
        } else {
            cout << a / b;
        }
        break;
        default:
        cout << "Invalid input";
    }
    
    return 0;
}