#include <bits/stdc++.h>
using namespace std;
int main() {
  int a[3], b[3];
  for (int i = 0; i < 3; i++) cin >> a[i];
  for (int i = 0; i < 3; i++) cin >> b[i];
  for (int i = 0; i < 3; i++) a[i] -= b[i];
  sort(a, a + 3);
  bool p = true;
  int t = 0;
  for (int i = 2; i >= 0; i--) {
    if (a[i] < 0) {
      if (t + a[i] < 0) p = false;
      t += a[i];
    } else
      t += a[i] / 2;
  }
  if (p)
    cout << "Yes";
  else
    cout << "No";
  cout << endl;
  return 0;
}
