console.log((args=>{
  let [S,T] = args.trim().split('\n');
  const SL = S.length, TL = T.length;
  if ( SL < TL ) return 'UNRESTORABLE';
  REST: for ( let i = SL - TL; i >= 0; i-- ) {
    for ( let j = 0; j < TL; j++ ) {
      if ( S[i+j] !== '?' && S[i+j] !== T[j] ) continue REST;
    }
    return (S.slice(0,i) + T + S.slice(i+TL)).replace(/\?/g,'a');
  }
  return 'UNRESTORABLE';
})(require('fs').readFileSync('/dev/stdin', 'utf8')));
