/**   Created by: Marcos Portales
          Codeforces User: marcosportales
          Country: Cuba
          Copyright                    */
#include<bits/stdc++.h>
using namespace std;
/// Pragmas:
#pragma GCC optimize("Ofast","unroll-loops","omit-frame-pointer","inline") //Optimization flags
#pragma GCC option("arch=native","tune=native","no-zero-upper") //Enable AVX
#pragma GCC target("avx2") //Enable AVX
/// Macros:
#define int long long
#define f first
#define s second
#define db(x) cerr << #x << ": " << (x) << '\n';
#define pb push_back
#define lb lower_bound
#define up upper_bound
#define all(x) x.begin() , x.end()
#define rall(x) x.rbegin() , x.rend()
#define enl '\n'
#define vi vector<int>
#define sz(a) int((a).size())
#define rep(i,n) for(int i=0;i<(n);i++)
#define repi(i,n) for(int i=(1);i<=(n);i++)
typedef pair<int,int> ii;
typedef long double ld;
typedef unsigned long long ull;
/// Constraints:
const int maxn = 200005;
const int mod = 1000000007;
const ld eps = 1e-9;
const int inf = ((1ll<<31ll)-1ll);
const int INF = 2000000000000000000ll;
const ld pi = acos(-1);
/// Prime Numbers:
// 2, 173, 179, 181, 197, 311, 331, 737, 1009, 2011, 2027, 3079, 4001, 10037, 10079, 20011, 20089;
// 100003, 100019, 100043, 200003, 200017, 1000003, 1000033, 1000037, 1000081;
// 2000003, 2000029, 2000039, 1000000007, 1000000021, 2000000099;
/// Functions:
#define lg2(x) 31 - __builtin_clz(x)
#define lgx(x,b) ( log(x) / log(b) )
/// Red-Black Tree Test.insert(x)late ---------------------------------
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
//using namespace __gnu_pbds;
//typedef tree < long long ,  null_type ,  less<long long> ,  rb_tree_tag ,  tree_order_statistics_node_update > ordered_set;
/// Quick Pow------------------------------------------------
int qpow(int b,int e){
    if( !e ) return 1;
    if( e & 1 ) return qpow(b,e-1) * b % mod;
    int pwur = qpow(b,e>>1);
    return (pwur * pwur) % mod;
}
int modinv(int x){
    return qpow(x,mod-2);
}

/// My Code -------------------------------------------------

int32_t main(){
    ios_base::sync_with_stdio(0); cin.tie(0);
    cout.setf(ios::fixed); cout.precision(0);
    srand(time(NULL));
    //freopen("a.in","r",stdin);
    //freopen("a.in","w",stdout);
    string s,t;
    cin >> s >>t;
    if(t.size()>s.size()){
        cout << "UNRESTORABLE" << endl;
        return 0;
    }

    string ans="{";
    for(int i = 0; i < s.size()-t.size()+1; i++) {
        bool a=true;
        for(int j = 0; j < t.size(); j++) {
            if(s[i+j]!=t[j] && s[i+j]!='?'){
                a=false;
            }
        }

        if(a){
            vector<char> y(s.size());
            for(int j = 0; j < s.size(); j++) {
                y[j]=s[j];
            }
            for(int j = i; j < i+t.size() ; j++) {
                y[j]=t[j-i];
            }
            for(int j = 0; j < s.size(); j++) {
                if(y[j]=='?') y[j]='a';
            }

            string q;
            for(int j = 0; j < s.size(); j++) {
                q += y[j];
            }
            if(ans>q) ans=q;
        }
    }

    if(ans=="{") cout << "UNRESTORABLE" << endl;
    else cout << ans << endl;

    return 0;
}


Measured memory_bytes: 3536