离奇Compile Error

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

这咋了