95pts求调

#include<bits/stdc++.h>
#define int long long
using namespace std;

//P3743 小鸟的设备
const int N=1e5+5;
int a[N],b[N];
int n,p;
bool check(double x){ //最多使用时间 
	double sum=0;
	for(int i=1;i<=n;i++){
		double y=b[i]-a[i]*x;
		if(y<=0)sum+=abs(y);
	}
	double c=p*x;
	return sum<=c;
}
signed main(){
	cin>>n>>p;
	for(int i=1;i<=n;i++)cin>>a[i]>>b[i];
	double l=0,r=1e10;
	while(r-l>1e-6){
		double mid=(l+r)/2.0;
		if(check(mid))l=mid;
		else r=mid;
	}
	if(r<1e9+1)printf("%.10lf",l);
	else cout<<-1;
	
	return 0;
}