#include <stdio.h>

#define SEC_PER_MIN 60

int main(void)
{
    int sec, min, left;

    printf("Convert seconds to minuts and seconds!\n");
    printf("Enter the number of seconds (<=0 to quit):\n");
    scanf("%d", &sec);

    while (sec > 0)
    {
        min = sec / SEC_PER_MIN;
        left = sec % SEC_PER_MIN;
        printf("%d seconds = %d:%d\n", sec, min, left);
        printf("Enter next value (<0 to quite):\n");
        scanf("%d", &sec);
    }
    printf("Done!\n");

    return 0;
}