AC了还有问题

#include<bits/stdc++.h>
#define int long long
using namespace std;
double a[100010],b[100010],n,p,l,r=1e18,mid,t,ans;
signed main() {
	cin>>n>>p;
	for(int i=1; i<=n; i++) {
		cin>>a[i]>>b[i];
		ans+=a[i]; 
	}
	if(ans<=p)cout<<-1<<endl;
	else {
		while(r-l>=0.000001) {
			mid=(l+r)/2;
			ans=0;
			for(int i=1; i<=n; i++)
				if(b[i]<a[i]*mid) {
					t=(a[i]*mid-b[i])/p;
					ans+=t;
				}
			if(ans<=mid)l=mid;
			else r=mid;
		}
		cout<<l<<endl;
	}
	return 0;
}