#include <bits/stdc++.h>
using namespace std;
int main() {
  iostream::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  ;
  long long n, t;
  cin >> n >> t;
  vector<pair<long long, long long> > v(n);
  double den = 0;
  for (long long i = (0); i < (n); ++i) {
    cin >> v[i].second;
    den += v[i].second;
  }
  for (long long i = (0); i < (n); ++i) cin >> v[i].first;
  sort(v.begin(), v.end());
  double sm = 0;
  for (long long i = (0); i < (n); ++i) {
    sm += v[i].first * v[i].second;
  }
  if (sm / den == (double)t) {
    cout << setprecision(8) << den;
    exit(0);
  }
  if ((double)sm / den > t) {
    for (long long i = n - 1; i >= 0; i--) {
      if ((double)(sm - v[i].first * v[i].second) / (den - v[i].second) > t) {
        sm -= v[i].first * v[i].second;
        den -= v[i].second;
        continue;
      } else {
        cout << setprecision(8)
             << den + (double)(sm - t * den) / (t - v[i].first);
        exit(0);
      }
    }
  } else {
    for (long long i = 0; i < n; i++) {
      if ((double)(sm - v[i].first * v[i].second) / (den - v[i].second) < t) {
        sm -= v[i].first * v[i].second;
        den -= v[i].second;
        continue;
      } else {
        cout << setprecision(8)
             << den + (double)(sm - t * den) / (t - v[i].first);
        exit(0);
      }
    }
  }
  cout << "0";
}
