#include <bits/stdc++.h>
using namespace std;
int main() {
  int blue, violet, orange;
  cin >> blue >> violet >> orange;
  int x, y, z;
  cin >> x >> y >> z;
  int check = 0;
  int spend = 0;
  int need = 0;
  check = blue - x;
  if (check >= 2)
    spend += (check / 2);
  else if (check <= 0)
    need += (check * -1);
  check = violet - y;
  if (check >= 2)
    spend += (check / 2);
  else if (check <= 0)
    need += (check * -1);
  check = orange - z;
  if (check >= 2)
    spend += (check / 2);
  else if (check <= 0)
    need += (check * -1);
  if (spend >= need)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
}
