#include <stdio.h>
int main()
{
int s,v,t;
char c = ':';
scanf("%d%d",&s,&v);
if(s % v == 0){t = s / v + 10;}
else{t = s / v + 10 + 1;}
int n = 8 * 60 + 24 * 60;
n = n - t;
if(n >= 24 * 60){n = n - 24 * 60;}
int a = n / 60;
int b = n % 60;
if(a < 10)
{
if(b < 10)
{
printf("%d%d%d%d%d",0,a,c,0,b);
}
else
{
printf("%d%d%d%d",0,a,c,b);
}
}
else 
{
if(b < 10)
{
printf("%d%d%d%d",a,c,0,b);
}
else
{
printf("%d%d%d",a,c,b);
}
}
return 0;
}