<?php
fscanf(STDIN, "%d", $NN);

$N = $NN;
$hours = 0;
$minutes = 0;
$seconds = 0;

// -- HOURS --
if ($N >= 3600) {
    $hours = $N/3600;
    $hours = (int) $hours;
    $N = $NN - $hours * 3600;
}

// -- MINUTES --
if ($N < 3600 && $N >= 60) {
    $minutes = $N/60;
    $minutes = (int) $minutes;
    $N = $N - $minutes * 60;
}

// -- SECONDS --
if ($N < 60) {
    $seconds = $N;
    $seconds = (int) $N;
}

// -- RESULT --
printf("%d:%d:%d\n", $hours, $minutes, $seconds);
?>