#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c, aa, bb, cc, s = 0;
  cin >> a >> b >> c >> aa >> bb >> cc;
  s = max(0, a - aa) / 2 + max(0, b - bb) / 2 + max(0, c - cc) / 2;
  s -= max(0, aa - a);
  s = s - max(0, bb - b);
  s = s - max(0, cc - c);
  if (s < 0)
    cout << "No" << endl;
  else
    cout << "Yes" << endl;
  return 0;
}
