前3AC,其他全WA

#include <bits/stdc++.h>
using namespace std;
int h=8,m=0,u,t;
double s;
int main(){
	cin>>s>>u;
	s=s/u;
	s=ceil(s);
	if((s+10)/60){
		h--;
		m=60-s-10;
	}else{
		h=h-ceil((s+10)/60);
		m=60-int(s+10)%60;
	}
	if(h-10<0){
		cout<<0<<h; 
	}else{
		cout<<h;
	}
	cout<<':';
	if(m-10<0){
		cout<<0<<m; 
	}else{
		cout<<m;
	}
	return 0;
}