rt

#include <bits/stdc++.h>
#define int unsigned long long
#define MAX 100000100
using namespace std;
int H[200000],A[200000];
bool check(int x,int n,int l,int s)
{
	int sum = 0;
	for(int i = 1;i <= n;i ++)
	{
		if(sum >= s) return true;
		if(H[i] >= l || x >= (l - H[i] - 1) / A[i] + 1) sum += H[i] + A[i] * x;
		if(sum >= s) return true;
	}
	return sum >= s;
}
signed main()
{
	int N,S,L,ccc= 0;
	cin >> N >> S >> L;
	for(int i = 1;i <= N;i ++)cin >> H[i];
	for(int i = 1;i <= N;i ++)cin >> A[i];
	int l = 2,r = MAX,mid,ans = 0;
	if(check(0,N,L,S))
	{
		cout << 0;
		return 0;
	}
	if(check(1,N,L,S))
	{
		cout << 1;
		return 0;
	}
	while(l <= r)
	{
		mid = (l + r) / 2;
		if(check(mid,N,L,S))
		{
			ans = mid;
			r = mid - 1;
		}
		else l = mid + 1;
	}
	cout << ans;
	return 0;
}