#ifndef ONLINE_JUDGE
#include "header.hpp"
#else
#include <bits/stdc++.h>
#include <atcoder/all>
#include <boost/multiprecision/cpp_int.hpp>
using cpp_int=boost::multiprecision::cpp_int;
#include <boost/multiprecision/cpp_dec_float.hpp>
template<unsigned size>using cpp_float=boost::multiprecision::number<boost::multiprecision::cpp_dec_float<size>>;
template<unsigned size>using cpp_double=boost::multiprecision::number<boost::multiprecision::cpp_dec_float<size,long long>>;
#endif

using namespace std;
using ll=long long;
inline void yn(bool x){if(x){cout<<"Yes"<<endl;}else{cout<<"No"<<endl;}}
#define double_out(x) fixed << setprecision(x)
template<class T> inline void erase_duplicate(vector<T>& A){sort(A.begin(),A.end());A.erase(unique(A.begin(),A.end()),A.end());}
inline ll powll(ll x,ll n){ll r=1;while(n>0){if(n&1){r*=x;};x*=x;n>>=1;};return r;}

using namespace std;
using ll=long long;


int main(){
    ll N,K;
    cin>>N>>K;
    vector<ll> A(N);
    for(ll i=0;i<N;i++){
        cin>>A[i];
    }
    vector<ll> B(N);
    for(ll i=0;i<N;i++){
        cin>>B[i];
    }
    vector<vector<ll>> div(N);
    for(ll i=0;i<N;i++){
        for(ll j=1;j*j<=A[i];j++){
            if(A[i]%j==0){
                div[i].push_back(j);
                if(A[i]/j!=j){
                    div[i].push_back(A[i]/j);
                }
            }
        }
        sort(div[i].begin(),div[i].end());
    }
    ll ac=1;
    ll wa=100001;
    for(ll i=0;i<60;i++){
        ll mid=(ac+wa)/2;
        ll cnt=0;
        for(ll j=0;j<N;j++){
            ll idx=lower_bound(div[j].begin(),div[j].end(),mid)-div[j].begin();
            ll tmp=1LL<<60;
            for(ll k=idx;k<div[j].size();k++){
                ll d=div[j][k];
                if(B[j]%d==0){
                    tmp=0;
                    break;
                }else{
                    tmp=min(tmp, d-(B[j]%d));
                }
            }
            cnt+=tmp;
            if(tmp==1LL<<60){
                break;
            }
        }
        if(cnt<=K){
            ac=mid;
        }else{
            wa=mid;
        }
    }
    cout<<ac<<endl;

}