#include<bits/stdc++.h>
using namespace std;
int s,u,xs=8,fz=0,sj_x,sj;
int main()
{
    cin>>s>>u;
    sj+=s/u+10;
    if(sj>=60)
    {
        sj_x=sj/60;
        xs-=sj_x;
        fz+=60;
		fz-=sj%60;
    }
    else
    {
        xs-=1;
        fz+=60-sj;
    }
    cout<<0<<xs<<':'<<fz;
	return 0;
}