#include<bits/stdc++.h>
using namespace std;
int main(){
	long long n,m;
	char x;
	cin>>n>>m>>x;
	if(x=='+') cout<<n+m;
	else if(x=='-') cout<<n-m;
	else if(x=='*') cout<<n*m;
	else if(x=='/'){
		if(n/m==0) cout<<"Divided by zero!";
		else cout<<n/m;
	}
	else cout<<"Invalid operator!"; 
}