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