
```cpp
#include <iostream>
#include <cstdio>
using namespace std;
int main(){
    double a,b;
    char o;
    cin>>a>>b>>o;
    if(o=='+'){
        printf("%.1f",a+b);
    }else if(o=='-'){
        printf("%.1f",a-b);
    }else if(o=='*'){
        printf("%.1f",a*b);
    }else if(o=='/'){
        if(b!=0){
            printf("%.1f",a/b);
        }else{
            cout<<"Divided by zero!"; 
        }
    }else{
        cout<<"Invalid operator!";
    }
    return 0;
}
```
