long parrot = 443 /*446*/; // module ID
embedded S firstLine() { ret (S) dm_rcall firstLine(parrot); }
embedded int numLines() { ret (int) dm_rcall numLines(parrot); }
LS rawLines = cast dm_rcall rawLines(parrot);
embedded ItIt<Int> lineCounter() { ret countIterator_exclusive(numLines()+2); }
embedded void checkGuess(IF1<Int, S> makeLine) {
  LS guess = map(lineCounter(), makeLine);
  print(guess);
  if (eq(takeFirst(guess, numLines()), rawLines)) {
    print("Solution: " + guess);
    dm_rcall suggest(parrot, get(guess, numLines()));
  }
}

// This is the code that is to be found
// by combining the 4 functions:
  
for (S s : allUniqueSubstrings(firstLine()))
  checkGuess(n -> concatTwoStrings_gen(s, plus1(n)));