过一天的情况不太会写/(ㄒoㄒ)/~~

#include <iostream>
#include <cmath>
using namespace std;

int main() {
	int s,v,n,m;
	cin>>s>>v;
	n=(480-ceil(s/v)-11)/60; 
	m=int((480-ceil(s/v)-11))%60;
	if(n<10&&m>10){
		cout<<0<<n<<":"<<m; 
	}else if(n<10&&m<10){
		cout<<0<<n<<":"<<0<<m;
	}else if(n>=10&&m<10){
		cout<<n<<":"<<0<<m;
	}else if(n>=10&&m>=10){
		cout<<n<<":"<<m;
	}else if(ceil(s/v)>470){
		cout<<"00:00";
	}
	return 0;
}