#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c;
  int x, y, z;
  cin >> a >> b >> c >> x >> y >> z;
  int s1, s2, s3;
  int f1, f2, f3;
  s1 = max(0, a - x);
  s2 = max(0, b - y);
  s3 = max(0, c - z);
  f1 = max(0, x - a);
  f2 = max(0, y - b);
  f3 = max(0, z - c);
  if ((f1 + f2 + f3) <= (s1 / 2 + s2 / 2 + s3 / 2)) {
    cout << "Yes";
  } else {
    cout << "No";
  }
  cout << endl;
  return 0;
}
