#include <bits/stdc++.h>
using namespace std;
template <class T>
ostream& operator<<(ostream& os, const vector<T>& v) {
  os << "[";
  for (int i = 0; i < v.size(); i++) os << v[i] << ",";
  os << "]";
  return os;
}
template <class T1, class T2>
ostream& operator<<(ostream& os, const pair<T1, T2>& p) {
  os << "(" << p.first << "," << p.second << ")";
  return os;
}
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  int a, b, c, x, y, z;
  cin >> a >> b >> c >> x >> y >> z;
  int p = 0, n = 0;
  if (a - x > 0)
    p += (a - x) / 2;
  else
    n += x - a;
  if (b - y > 0)
    p += (b - y) / 2;
  else
    n += y - b;
  if (c - z > 0)
    p += (c - z) / 2;
  else
    n += z - c;
  cout << (p >= n ? "Yes" : "No") << endl;
}
