#include <bits/stdc++.h>
using namespace std;
const int N = 100005;
const int MAX = 100000000;
int n;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int a, b, c, x, y, z;
  cin >> a >> b >> c;
  cin >> x >> y >> z;
  a -= x;
  b -= y;
  c -= z;
  if (a < 0) {
    if (b > 0) {
      int k = min(-a, (b >> 1));
      a += k;
      b -= (k << 1);
    }
    if (a < 0 && c > 0) {
      int k = min(-a, (c >> 1));
      a += k;
      c -= (k << 1);
    }
    if (a < 0) {
      cout << "No";
      return 0;
    }
  }
  if (b < 0) {
    if (c > 0) {
      int k = min(-b, (c >> 1));
      b += k;
      c -= (k << 1);
    }
    if (b < 0 && a > 0) {
      int k = min(-b, (a >> 1));
      b += k;
      a -= (k << 1);
    }
    if (b < 0) {
      cout << "No";
      return 0;
    }
  }
  if (c < 0) {
    if (b > 0) {
      int k = min(-c, (b >> 1));
      c += k;
      b -= (k << 1);
    }
    if (c < 0 && a > 0) {
      int k = min(-c, (a >> 1));
      c += k;
      a -= (k << 1);
    }
    if (c < 0) {
      cout << "No";
      return 0;
    }
  }
  if (a >= 0 && b >= 0 && c >= 0)
    cout << "Yes";
  else
    cout << "No";
  return 0;
}
