#include <bits/stdc++.h>
using namespace std;
int main() {
  long int a, b, c, x, y, z;
  cin >> a >> b >> c >> x >> y >> z;
  int extra[3];
  int sum = 0;
  extra[0] = a - x;
  extra[1] = b - y;
  extra[2] = c - z;
  for (int i = 0; i < 3; i++)
    if (extra[i] > 0)
      sum += extra[i] / 2;
    else
      sum += extra[i];
  if (sum >= 0)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
  return 0;
}
