#include <bits/stdc++.h>
using namespace std;
const int N = 1e5;
const int inf = 1e9 + 7;
int main() {
  int a, b, c;
  cin >> a >> b >> c;
  int x, y, z;
  cin >> x >> y >> z;
  int h = 0;
  if (a >= x) h += ((a - x) / 2);
  if (b >= y) h += ((b - y) / 2);
  if (c >= z) h += ((c - z) / 2);
  int p = 0;
  if (a < x) p += (x - a);
  if (b < y) p += (y - b);
  if (c < z) p += (z - c);
  if (p <= h)
    cout << "Yes";
  else
    cout << "No";
}
