#include <bits/stdc++.h>

using namespace std;

using i64=long long;
using u64=unsigned long long;
using db=double;
using vi=vector<int>;
using pii=pair<int,int>;

template<typename T>
inline T read(){
    T x=0,f=0;char ch=getchar();
    while(!isdigit(ch)) f|=(ch=='-'),ch=getchar();
    while(isdigit(ch)) x=(x*10)+(ch^48),ch=getchar();
    return !f?x:-x;
}

#define rdi read<int>
#define rdi64 read<i64>
#define fi first
#define se second
#define mp make_pair
#define pb push_back

const int N=1e5+10;

int n;
i64 m,v[N],a[N];

void init(){
}

namespace TEST{
    bool check(int s){
        i64 sum=s,lst=0;
        for(int i=2;i<=n;i++){
            i64 L=lst+v[i],R=L+a[i];
            i64 mi=(L*s+v[1]-1)/v[1],mx=min((R*s+v[1]-1)/v[1],m);
            if(mi>m) return false;
            i64 mxr=-1,p,c;
            for(i64 cnt=mi;cnt<=mx;cnt++){
                i64 q=min(cnt*v[1]/s,R);
                i64 r=(q*s-1)%v[1]+1;
                if(r>mxr) mxr=r,p=q,c=cnt;
            }
            lst=p-L,sum+=c-1;
        }
        return sum<=m;
    }
    void solve(){
        v[1]+=a[1]+a[n],a[1]=a[n]=0;
        int l=0,r=m;
        while(l<r){
            int mid=(l+r+1)/2;
            if(check(mid)) l=mid;
            else r=mid-1;
        }
        cout<<l<<endl;
    }
}

int main(){
#ifdef LOCAL
    freopen("1.in","r",stdin);
    freopen("1.out","w",stdout);
#endif
    n=rdi(),m=rdi();
    for(int i=1;i<=n;i++) v[i]=rdi();
    for(int i=1;i<=n;i++) a[i]=rdi();
    TEST::solve();
    return 0;
}