#include<stdio.h>

#include<stdio.h>
int main(){
	int s,v;
	float a;
	int b,c,h,min;
	scanf("%d %d",&s,&v);
	a=s/v;
	b=a/60;
	c=(int)a%60;
	if(s/v!=0)
	c++;
	h=7-b;
	min=50-c;
	printf("%.2d:%.2d",h,min);
	return 0;
}

int main(){ int s,v; float a; int b,c,h,min; scanf("%d %d",&s,&v); a=s/v; b=a/60; c=(int)a%60; if(s/v!=0) c++; h=7-b; min=50-c; printf("%.2d:%.2d",h,min); return 0; }