#include <bits/stdc++.h>
using namespace std;
int getn() {
  int h;
  scanf("%d", &h);
  return h;
}
template <class T, class U>
ostream& operator<<(ostream& out, const pair<T, U>& par) {
  cout << par.first << " " << par.second << endl;
  return out;
}
template <class T>
ostream& operator<<(ostream& out, const vector<T>& v) {
  for (int i = 0; i < v.size(); i++) {
    if (i) cout << " ";
    cout << v[i];
  }
  cout << endl;
  return out;
}
int main() {
  int n = 0, minus = 0;
  int a, b, c;
  cin >> a >> b >> c;
  int x, y, z;
  cin >> x >> y >> z;
  if (a < x)
    n += x - a;
  else
    minus += (a - x) / 2;
  if (b < y)
    n += y - b;
  else
    minus += (b - y) / 2;
  if (c < z)
    n += z - c;
  else
    minus += (c - z) / 2;
  if (0) cout << minus << " " << n << endl;
  if (minus - n < 0)
    cout << "No" << endl;
  else
    cout << "Yes" << endl;
}
