#include <bits/stdc++.h>
using namespace std;

const int N = 5e5+10;

int l1,l2,cnt1[30],cnt2[30],cha,mb1,mb2,cuo,cuodui;
char s1[N],s2[N],s3[N];

vector<int> q;

signed main(){
	freopen("troublekey.in","r",stdin);
	freopen("troublekey.out","w",stdout);
	mb1=mb2=cuo=cuodui=-1;
	cin>>(s1+1);
	l1=strlen(s1+1);
	for(int i=1;i<=l1;i++){
		cnt1[s1[i]-'a']++; 
	}
	cin>>(s2+1);
	l2=strlen(s2+1);
	for(int i=1;i<=l2;i++){
		cnt2[s2[i]-'a']++;
	}
	cha=l1-l2;
	for(int i=0;i<26;i++){
		if(cnt1[i]!=0){
			if(cnt2[i]==0){
				if(cnt1[i]==cha)mb1=i;
				else cuo=i;
//				q.push_back(i);
			}
		}
		if(cnt1[i]==0){
			if(cnt2[i]!=0){
				cuodui=i;
			}
		}
	}
	cout<<(char)(cuo+'a')<<" "<<(char)(cuodui+'a')<<endl;
	if(cha)cout<<(char)(mb1+'a');
	else cout<<'-'; 
	return 0;
}