// dfmt off
T lread(T=long)(){return readln.chomp.to!T;}T[] lreads(T=long)(long n){return iota(n).map!((_)=>lread!T).array;}
T[] aryread(T=long)(){return readln.split.to!(T[]);}void arywrite(T)(T a){a.map!text.join(' ').writeln;}
void scan(L...)(ref L A){auto l=readln.split;foreach(i,T;L){A[i]=l[i].to!T;}}alias sread=()=>readln.chomp();
void dprint(L...)(lazy L A){debug{auto l=new string[](L.length);static foreach(i,a;A)l[i]=a.text;arywrite(l);}}
static immutable MOD=10^^9+7;alias PQueue(T,alias l="b<a")=BinaryHeap!(Array!T,l);import std;
// dfmt on

void main()
{
    auto S = sread();
    auto T = sread();
    bool eq(string s, string t)
    {
        foreach (i; 0 .. s.length)
        {
            if (s[i] == '?' || t[i] == '?' || s[i] == t[i])
                continue;
            return false;
        }
        return true;
    }

    foreach_reverse (i; 0 .. S.length - T.length + 1)
    {
        dprint(S[i .. i + T.length], T);
        if (eq(S[i .. i + T.length], T))
        {
            char[] U = new char[](S.length);
            foreach (j; 0 .. S.length)
            {
                if (i <= j && j < i + T.length)
                {
                    U[j] = T[j - i];
                    continue;
                }
                if (S[j] == '?')
                {
                    U[j] = 'a';
                    continue;
                }
                U[j] = S[j];
            }
            writeln(U);
            return;
        }
    }
    writeln("UNRESTORABLE");
}
