#include<iostream>
using namespace std;

class calculator{
    public:
    int operators(int t, int a, int b){
        if (t == 1) return a + b;
        if (t == 2) return a - b;
        if (t == 3) return a * b;
        if (t == 4) return a / b;
        return 0;
    }
    double operator(int t, double a, double b){
         if (t == 1) return a + b;
        if (t == 2) return a - b;
        if (t == 3) return a * b;
        if (t == 4) return a / b;
        return 0;
    }
};
int main(){
    int t;
    cin >> t;
    
    if(t <= 0){
        cout << "Invalid input";
        return 0;
    }
    
    double a, b;
    cin >> a >> b;
    
    if(t == a && b == (int)b){
        cout << c.operator(t,(int)b){
        }else{
            cout << c.operator(t, a, b);
    }
    return 0;
}