#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c, x, y, z;
  cin >> a >> b >> c;
  cin >> x >> y >> z;
  int m = 0, p = 0;
  ;
  if (z > c) m = m + z - c;
  if (y > b) m = m + y - b;
  if (x > a) m = m + x - a;
  p = max(a - x, 0) / 2 + max(b - y, 0) / 2 + max(c - z, 0) / 2;
  if (p >= m)
    cout << "Yes";
  else
    cout << "No";
}
