#include "stdio.h"


int main(){
    
    int s,v,minute,hour,t;
    scanf("%d %d",&s,&v);
    t = s/v;
	if((double)s/v>t)
	{
		t++;
	}
    minute = 1920;
    if(t<=1920)
    {
    	minute -= (t+10);
    	hour = minute/60;
    	if(hour>24)
    	{
    		hour -= 24;
		}
    	minute %= 60;
    	if(hour<10)
    	{
    		printf("0");
		}
		printf("%d:",hour);
		if(minute<10)
		{
			printf("0");
		}
		printf("%d",minute);
	}
    else
    return 0;
}

请大佬们看看咋改