// #include <bits/stdc++.h>
#include <iostream>
#include <vector>
#include <string>
#include <set>
#include <map>
#include <queue>
#include <algorithm>
#include <cassert>
#include <functional>
#include <numeric>
#include <bitset>
#include <iomanip>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll,ll> PP;
// #define MOD 1000000007
#define MOD 998244353
#define INF 2305843009213693951ll
#define PI 3.141592653589
#define setdouble setprecision
#define REP(i,n) for(ll i=0;i<(n);++i)
#define OREP(i,n) for(ll i=1;i<=(n);++i)
#define RREP(i,n) for(ll i=(n)-1;i>=0;--i)
#define ORREP(i,n) for(ll i=(n);i>=1;--i)
#define rep(i,a,b) for(ll i=(a);i<=(b);++i)
#define ALL(v) (v).begin(), (v).end()
#define chmin(k,m) k = min(k,m)
#define chmax(k,m) k = max(k,m)
#define GOODBYE do { cout << "-1" << endl; return 0; } while (false)
#define MM <<" "<<
#define Endl endl

std::vector<long long> divisor_enum(long long N){
    // Copyright (c) 2023 0214sh7
    // https://github.com/0214sh7/library/
    std::vector<long long> R;
    if(N<=0)return R;
    long long s=0;
    for(long long i=1;i*i<=N;i++){
        if(N%i==0){
            R.push_back(i);
            if(i*i!=N)s++;
        }
    }
    for(long long i = s-1;i>=0;i--){
        R.push_back(N/R[i]);
    }
    return R;
}

int main(void){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    ll N,K;
    cin >> N >> K;
    vector<ll> A(N);
    ll Amin = INF;
    REP(i,N){
        cin >> A[i];
        Amin = min(Amin,A[i]);
    }
    vector<ll> B(N);
    REP(i,N){cin >> B[i];}

    vector<vector<ll>> dA(N);
    REP(i,N){
        dA[i] = divisor_enum(A[i]);
        reverse(ALL(dA[i]));
    }

    // スコアを mid 以上にするのに K 回以下で済むか
    ll ok = 0, ng = Amin+1, mid;
    while(abs(ok-ng)>1){

        mid = (ok+ng)/2;
        ll sum = 0;
        REP(i,N){
            if(gcd(A[i],B[i]) >= mid)continue;
            ll m = INF;
            for(ll d:dA[i]){
                if(d < mid)break;
                ll tmp = (d-(B[i]%d))%d;
                m = min(m,tmp);
            }
            sum += m;
        }

        // cout << ok MM ng MM mid MM sum << endl;
        if(sum <= K){
            ok = mid;
        }else{
            ng = mid;
        }
    }

    cout << ok << endl;

    return 0;
    
}