#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<vector>
#include<queue>
#include<set>
#include<map>
#include<utility>
#include<sstream>
#include<cctype>
#include<cmath>
#include<algorithm>
using namespace std;

#define ALL(x) (x).begin(),(x).end()
#define RALL(x) (x).rbegin(), (x).rend()
#define rev(i,n) for(int (i)=(n-1);(i)>=0;(i)--)
#define repp(i,n) for(int (i)=1;(i)<=(n);(i)++)
#define rep(i,n) for(int (i)=0;(i)<(n);(i)++)
#define rev(i,n) for(int (i)=(n-1);(i)>=0;(i)--)
#define clr(a) memset((a), 0 ,sizeof(a))


typedef pair<int,int> P;
typedef vector<pair<int,string> > pii;
typedef map<string,int> mi;



int main(){
	string s,s2,s3,S,S2,S3;
	cin >> s >> s2 >> s3 >> S >> S2 >> S3;
	if(s2.size()>S2.size()) cout << s << endl;
	else if(s2.size()<S2.size()) cout << S << endl;
	else if(s2.size()==S2.size()){
		for(int i=0;i<s2.size();i++){
			if(s2[i]>S2[i]){
				cout << s << endl;
				return 0;
			}else if(s2[i]<S2[i]){
				cout << S << endl;
				return 0;
			}
		}
		cout << -1 << endl;
	}
	return 0;
}