#include <iostream>
using namespace std;

int main()
{
    double a,b;
    char c;
    cin>>a>>b>>c;
    if(b==0&&c=='/'){
        cout<<"Divided by zero!";
        return 0;
    }
    switch(c){
        case '+': cout<<a+b; break;
        case '-': cout<<a-b; break;
        case '*': cout<<a*b; break;
        case '/': cout<<a/b; break;
        default:
            cout<<"Invalid operator!";
    }
    return 0;
}