#include
using namespace std;
int main() {
char ch;
int n1, n2;
cin>>ch;
do{
if (ch == ‘x’ || ch == ‘X’){
cout<<“Invalid operation. Try again”<<endl;
break;
}
if (ch == ‘’ || ch == ‘/’ || ch == ‘+’ || ch == ‘-’ || ch == ‘%’){
cin>>n1>>n2;
switch(ch){
case '’ : cout<<n1*n2<<endl;
break;
case ‘+’ : cout<<n1+n2<<endl;
break;
case ‘-’ : cout<<n1-n2<<endl;
break;
case ‘/’ : cout<<n1/n2<<endl;
break;
case ‘%’ : cout<<n1 %n2<<endl;
}
cin>>ch;
}
else {
cout<<"Invalid operation. Try again"<<endl;
cin>>ch;
}
}while(ch != 'X' && ch != 'x');
return 0;
}