#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
template<typename T>bool chmax(T &x, T y){if(x>=y)return false;x=y;return true;}
template<typename T>bool chmin(T &x, T y){if(x<=y)return false;x=y;return true;}

int main(){
  long long N, K;
  cin >> N >> K;
  vector<long long> A(N), B(N);
  rep(i, N)cin >> A[i];
  rep(i, N)cin >> B[i];
  vector<set<int>> s(N);
  rep(i, N){
    for(int j = 1; j*j <= A[i]; j++)if(A[i]%j==0){
      s[i].insert(j);
      s[i].insert(A[i]/j);
    }
  }
  long long ok = 1, ng = 1234567890, mi;
  while(ng-ok>1){
    mi = (ng+ok)/2;
    long long c = 0;
    rep(i, N){
      long long d = 123456789012;
      auto itr = s[i].lower_bound(mi);
      while(itr!=s[i].end()){
        chmin(d, (B[i]+*itr-1)/(*itr)*(*itr)-B[i]);
        itr++;
      }
      c += d;
    }
    if(c>K)ng = mi;
    else ok = mi;
  }
  cout << ok << endl;
}