#include <bits/stdc++.h>
using namespace std;
bool DBG = true;
template <typename T, typename S>
std::ostream& operator<<(std::ostream& os, const std::pair<T, S>& p) {
  os << "(" << p.first << ", " << p.second << ")";
  return os;
}
template <typename T>
std::ostream& operator<<(std::ostream& os, const std::vector<T>& vector) {
  for (size_t i = 0; i < vector.size(); ++i) {
    os << vector[i] << " ";
  }
  return os;
}
template <typename T>
std::ostream& operator<<(std::ostream& os,
                         const std::vector<std::vector<T>>& vector) {
  for (size_t i = 0; i < vector.size(); ++i) {
    os << vector[i] << endl;
  }
  return os;
}
void Yes() { cout << "Yes" << endl; }
void No() { cout << "No" << endl; }
int main() {
  ios_base::sync_with_stdio(false);
  vector<int> v(3);
  vector<int> w(3);
  for (int i = 0; i < (int)(v.size()); ++i) {
    cin >> v[i];
  }
  for (int i = 0; i < (int)(w.size()); ++i) {
    cin >> w[i];
  }
  int s = 0;
  for (int i = 0; i < (int)(v.size()); ++i) {
    int diff = v[i] - w[i];
    if (diff >= 0) {
      s += diff / 2;
    } else {
      s += diff;
    }
  }
  if (s >= 0) {
    Yes();
  } else {
    No();
  }
  return 0;
}
