#include<iostream>
#include<algorithm>
using namespace std;
const int maxn=200+2;
int tmp,cnt;
string str[maxn];
int main(){
	for (char ch='a';ch<='c';ch++){
		cin>>tmp;
		while (tmp--) str[cnt++]+=ch;
	}
	while (cnt>1){
		sort(str,str+cnt);
		str[0]+=str[--cnt];
	}
	cout<<str[0];
	return 0;
}