#include <bits/stdc++.h>
using namespace std;
int main() {
  pair<int, int> a[3];
  for (int i = 0; i < 3; i++) cin >> a[i].first;
  for (int i = 0; i < 3; i++) cin >> a[i].second;
  int x0, y0, z0;
  x0 = a[0].first - a[0].second;
  y0 = a[1].first - a[1].second;
  z0 = a[2].first - a[2].second;
  int x1, y1, z1;
  x1 = a[0].second - a[0].first;
  y1 = a[1].second - a[1].first;
  z1 = a[2].second - a[2].first;
  int k1 = 0, k2 = 0;
  if (x0 > 0) k1 += x0 / 2;
  if (y0 > 0) k1 += y0 / 2;
  if (z0 > 0) k1 += z0 / 2;
  if (x1 > 0) k2 += x1;
  if (y1 > 0) k2 += y1;
  if (z1 > 0) k2 += z1;
  if (k1 < k2)
    cout << "No";
  else
    cout << "Yes";
  return 0;
}
