#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  int a, b, c, x, y, z;
  cin >> a >> b >> c >> x >> y >> z;
  int cnt = 0;
  if (a > x) cnt += (a - x) / 2;
  if (b > y) cnt += (b - y) / 2;
  if (c > z) cnt += (c - z) / 2;
  if (a < x)
    if (x - a <= cnt) {
      cnt -= x - a;
      a += x - a;
    }
  if (b < y)
    if (y - b <= cnt) {
      cnt -= y - b;
      b += y - b;
    }
  if (c < z)
    if (z - c <= cnt) {
      cnt -= z - c;
      c += z - c;
    }
  if (a >= x && b >= y && c >= z)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
  return 0;
}
