<?php
$T = explode(":", trim(fgets(STDIN)));
$h = $T[0];
$m = $T[1];
$ansh = 0;
$ansm = 0;
$m += 5;
if($m >= 60) {
  $ansh = $h + 1;
  $ansm = ($m) % 60;
  if($ansh > 23) $ansh = 0;
} else {
  $ansh = $h;
  $ansm = $m;
}
if(strlen($ansh) < 2) $ansh = "0" . $ansh;
if(strlen($ansm) < 2) $ansm = "0" . $ansm;
print($ansh . ":" . $ansm);
?>