// min_sec.c -- converts seconds to minutes and seconds
#include <stdio.h>
#define SEC_PER_MIN 60            // seconds in a minute 
int main(void)
{
    int sec, min, left;

    printf("Convert seconds to minutes and seconds!\n");
    printf("Enter the number of seconds (<=0 to quit):\n");
    scanf("%d", &sec);            // read number of seconds 
    while (sec > 0) 
    {
        min = sec / SEC_PER_MIN;  // truncated number of minutes
        left = sec % SEC_PER_MIN; // number of seconds left over
        printf("%d seconds is %d minutes, %d seconds.\n", sec, 
                min, left);
        printf("Enter next value (<=0 to quit):\n");
        scanf("%d", &sec);           
    }
    printf("Done!\n");
  
    return 0;
}