死循环 求助 T_T

#include<bits/stdc++.h>
using namespace std;
unsigned long long c,i,l,r=1000000000000000000,n,s,k,h[1000001],a[1000001],mid;
int ef(){
	while(l<r){
		mid=(l+r)/2;
		c=0;
		for(i=1;i<=n;i++)
			if(h[i]+a[i]*mid>=k)
				c+=h[i]+a[i]+mid;
		if(c>=s)
			l=mid;
		else
			r=mid-1;
	}
	return l;
}
int main(){
	scanf("%llu%llu%llu",&n,&s,&k); 
	for(i=1;i<=n;i++)
		scanf("%llu",&h[i]); 
	for(i=1;i<=n;i++)
		scanf("%llu",&a[i]); 
	cout<<ef();
	return 0;
}