#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define fi first
#define se second
string s;
int n;
ll m;
ll v[100005],a[100005];
ll vv[100005];
bool check(ll s){
	//cout << "check " << s << endl;
	for(int i=1; i<=n ;i++) vv[i]=v[i];
	ll v=vv[1];
	for(int i=2; i<=n ;i++){
		ll mn=s%v,mx=s%v;
		ll cn=1,cx=1;
		ll hp=a[i];
		
		ll frog=vv[i]*s%v;
		while(hp>=cn && mn>0){
			ll rep=(v-frog)/mn;
			rep=min(rep,hp/cn);
			frog+=rep*mn;
			hp-=rep*cn;
			if(mn+mx<v){
				ll rep=(v-mx-1)/mn;
				mx+=rep*mn;
				cx+=rep*cn;
			}
			else{
				ll rep=mn/(v-mx);
				ll shave=(frog+mn-v + (v-mx) - 1)/(v-mx);
				rep=min(rep,shave);
				mn-=rep*(v-mx);
				cn+=rep*cx;
			}
		}
		//cout << "hello " << i << ' ' << a[i]-hp << endl;
		vv[i]+=a[i]-hp;
		if(i!=n) vv[i+1]+=hp;
	}
	ll frog=0;
	for(int i=2; i<=n ;i++){
		//cout << vv[i] << ' ';
		if(vv[i]>0) frog+=(vv[i]*s-1)/v;
	}
	//cout << endl;
	return (frog<=m-s);
}
int main(){
	ios::sync_with_stdio(false);cin.tie(0);
	cin >> n >> m;++m;
	for(int i=1; i<=n ;i++) cin >> v[i];
	for(int i=1; i<=n ;i++) cin >> a[i];
	v[1]+=a[1]+a[n];
	a[1]=a[n]=0;
	ll l=0,r=m;
	while(l!=r){
		ll mid=(l+r+1)/2;
		if(check(mid)) l=mid;
		else r=mid-1;
	}
	cout << l << '\n';
}