第九个点过不去，能帮忙康康吗QWQ

#include<bits/stdc++.h>
using namespace std;
int s,v;
double m;
int n,a,t,b;
int main()
{
	cin>>s>>v;
	n=(8*60-1)+24*60;
	t=ceil(s/v)+10;
	n=n-t;
	if(n>=24*60) n-=24*60;
	b=n%60;
	a=n/60;
	if(a<10)
	{
		if(b<10) cout<<"0"<<a<<":0"<<b;
		else cout<<"0"<<a<<":"<<b;
	}
	else
	{
		if(b<10) cout<<a<<":0"<<b;
		else cout<<a<<":"<<b;
	}
}