a

#include <bits/stdc++.h>
using namespace std;
long long a,b,c;
int main(){
cin>>a>>b>>c;
long long s[6]={a,b,c};
sort(s,s+3);
a = s[0];
b = s[1];
c = s[2];
if(a+b<=c){
cout<<"error";
}else{
if(ab&&bc){
cout<<"aaa";
}else if(ab||ac||c==b){
cout<<"aab";
}else{
cout<<"abc";
}
}
}