#include <bits/stdc++.h>
using namespace std;
string a,b;
unordered_map<char,int>mp;
char ans1;
int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
    freopen("troublekey1.in","r",stdin);
    freopen("troublekey1.out","w",stdout);	
    cin>>a>>b;
    for(int i=0;i<=a.size()-1;i++){
        mp[a[i]]=1;
    }     
    if(a.size()==b.size()){
        pair<char,char>ans2;
        for(int i=0;i<=b.size()-1;i++){
            if(mp[b[i]]==0){
                ans2={a[i],b[i]};
                break;
            }
        }
        cout<<ans2.first<<" "<<ans2.second<<"\n";        
        cout<<"-";
        return 0;
    }
    for(int i=0;i<=b.size()-1;i++){
        if(mp[b[i]]==0){
            ans1=b[i];
            break;
        }
    }    
    for(int i=0;i<26;i++){
        string d=a;
        while (d.find('a'+i) != -1){
            d.erase(d.find('a'+i),1);
        }
        int ncnt=0;
        char anss;
        if(d.size()==b.size()){
            for(int j=0;j<d.size();j++){
                if(d[j]!=b[j]){
                    anss=d[j];
                    d[j]=ans1;
                }
            }            
        }
        char an=i+'a';
        if(d==b){
            cout<<anss<<" "<<ans1<<"\n"<<an;
            break;
        }
    }
	 

    return 0;
}