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