不知道为啥就全WA了QAQ 下面是源代码

#include<bits/stdc++.h>
using namespace std;
int main()
{
	int t,h,m;
	double s,v,t1,t2;
	cin>>s>>v;
	t1=s/v;
	t=t1;
	t2=t;
	if(t1>t2)
	{
		t+=1;
	}
	t+=10;
	if(t<60)
	{
		cout<<7<<":"<<60-t;
	}
	else
		if(60<t<480)
		{
			h=t/60;
			m=t-h*60;
			cout<<8-m-1<<":"<<60-m;
		}
		else
		{
	  		if(t==480)
	  		{
	  			cout<<"00:00";
	  		}
	  		else
	  		{
	  			h=t/60;
	  			m=t-h*60;
	  			h=h-8;
	  			if(24-h>=10)
	  				if(60-m>=10)
	  					cout<<24-h-1<<":"<<60-m;
	  				else
	  				    cout<<24-h-1<<":0"<<60-m;
	  			else
	  			    cout<<"0"<<24-h-1<<":0"<<60-m;
			}
		}
	return 0;
}

求指出错误并给予修改思路 如果能给几组样例就更好啦 谢谢大佬awa