RE,不知道哪里错了

#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!"; 
}