<?php

$Z = 5 - 2; // f - c == number of Zeros
for ($k = 0; $k <= $Z; $k++) {
  for ($m = 0; $m <= ($Z-$k); $m++) {
    $n = $Z - $k - $m;
    echo str_repeat("0", $k);
    echo 1;
    echo str_repeat("0", $m);
    echo 1;
    echo str_repeat("0", $n);
    echo "\n";
  }
}

?>