第4個測資沒過

新手求編小力一點><

#include <iostream>
using namespace std;

int main(){
int a,b,c;
while(cin>>a>>b>>c){
if(a==0 && b==0){
if(c==0)
cout<<"AND"<<endl<<"OR"<<endl<<"XOR"<<endl;}
else if(a==0 && b!=0){
if(c==0)
cout<<"AND"<<endl;
else
cout<<"OR"<<endl<<"XOR"<<endl;
}
else if(a!=0 && b==0){
if(c==0)
cout<<"AND"<<endl;
else
cout<<"OR"<<endl<<"XOR"<<endl;
}
else if(a!=0 && b!=0){
if(c==0)
cout<<"XOR"<<endl;
else
cout<<"AND"<<endl<<"OR"<<endl;
}
else{
cout<<"IMPOSSIBLE"<<endl;}
}
return 0;
}

a = 0, b = 0, c != 0 會沒輸出