#include <bits/stdc++.h>
using namespace std;
int main() {
  int a[3];
  int x[3];
  int last = 0;
  cin >> a[0] >> a[1] >> a[2];
  cin >> x[0] >> x[1] >> x[2];
  for (int i = 0; i < 3; ++i) {
    int t = a[i] - x[i];
    if (t > 0) t /= 2;
    last += t;
  }
  if (last < 0)
    cout << "No\n";
  else
    cout << "Yes\n";
  return 0;
}
