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