let clock sec = 
let hour = sec/3600 in
let minute = (sec mod 3600) / 60 in
let second = sec mod 60 in
print_int hour;
print_string ":";
print_int minute;
print_string ":";
print_int second;
print_string "\n";;

let () = 
clock (int_of_string (read_line()));;
