import core.bitop, std.algorithm, std.ascii, std.bigint, std.conv,
    std.functional, std.math, std.numeric, std.range, std.stdio, std.string,
    std.random, std.typecons, std.container;

ulong MAX = 100_100, MOD = 1_000_000_007, INF = 1_000_000_000_000;
alias sread = () => readln.chomp();
alias lread(T = long) = () => readln.chomp.to!(T);
alias aryread(T = long) = () => readln.split.to!(T[]);
alias Pair = Tuple!(long, "a", long, "b");
alias PQueue(T, alias less = "a<b") = BinaryHeap!(Array!T, less);

void main()
{
    auto s = sread();
    auto t = sread();
    if (s.length < t.length)
    {
        writeln("UNRESTORABLE");
        return;
    }
    long insert = -1;
    foreach (i; iota(s.length - t.length + 1))
    {
        if (is_pass(s[i .. i + t.length], t))
            insert = i;
    }
    if (insert > 0)
    {
        fill_a(s, t, insert).writeln();
    }
    else
    {
        writeln("UNRESTORABLE");
    }
}

bool is_pass(string pat, string str)
{
    bool ret = true;
    foreach (i; iota(pat.length))
    {
        if (pat[i] == '?')
            continue;

        ret &= (pat[i] == str[i]);
    }
    return ret;
}

auto fill_a(string s, string t, long insert)
{
    string ret;
    foreach (i, e; s)
    {
        if (i >= insert && i < insert + t.length)
        {
            ret ~= t[i - insert];
        }
        else
        {
            ret ~= (e == '?' ? 'a' : e);
        }
    }
    return ret;
}

void scan(TList...)(ref TList Args)
{
    auto line = readln.split();
    foreach (i, T; TList)
    {
        T val = line[i].to!(T);
        Args[i] = val;
    }
}
