c20210713 uri1019.c

#include <stdio.h>

int main(){
    int s;
    scanf("%d", &s);

    printf("%d:%d:%d\n", s/3600, (s-(s/3600)*3600)/60, s-(s/3600)*3600-((s-(s/3600)*3600)/60)*60);

    return 0;
}