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