#include <bits/stdc++.h>
using namespace std;
int main() {
  int p1 = 0;
  vector<int> tab(3);
  for (int i = 0; i < 3; i++) cin >> tab[i];
  for (int i = 0; i < 3; i++) {
    int a;
    cin >> a;
    tab[i] = tab[i] - a;
    if (tab[i] > 0) {
      tab[i] = tab[i] / 2;
    }
    p1 = tab[i] + p1;
  }
  if (p1 >= 0) {
    cout << "Yes";
  } else {
    cout << "No";
  }
}
