#include<iostream>
#include<cmath>
using namespace std;

class calculator
{
    public:
    int operate(int t, int a, int b)
    {
        switch(t)
        {
            case 1: return a+b;
            case 2: return a-b;
            case 3: return a*b;
            case 4: return a/b;
        }
        return 0;
    }
    double operate(int t, double a, double b)
    {
        switch(t)
        {
            case 1: return a+b;
            case 2: return a-b;
            case 3: return a*b;
            case 4: return a/b;
        }
        return 0.0;
    }
};
bool isinteger(double x)
{
    return floor(x)==x;
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int t;
    double a,b;
    if(!(cin>>t)||!(cin>>a)||!(cinb>>b)||t<=0||t>4)
    {
        cout<<"Invalid input";
        return 0;
    }
    if(t==4&&b==0.0)
    {
        cout<<"Division by zero";
        return 0;
    }
    calculator calc;
    
    if(isinteger(a)&&isinteger(b))
    {
        int ai=static_cast<int>(a);
        int bi=static_cast<int>(b);
        int result=calc.operate(t,ai,bi);
        cout<<result;
    }
    else
    {
        double result=calc.operate(t,a,b);
        cout<<result;
    }
    return 0;
}