#include <bits/stdc++.h>
using namespace std;
void Solve() {
  long long a[3];
  for (signed i = 0; i < (3); i++) cin >> a[i];
  long long cnt = 0;
  for (signed i = 0; i < (3); i++) {
    long long q;
    cin >> q;
    a[i] -= q;
    if (a[i] >= 0)
      cnt += a[i] / 2;
    else
      cnt += a[i];
  }
  cout << (cnt >= 0 ? "Yes" : "No");
}
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  Solve();
  return 0;
}
