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