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