#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  int a, b, c, x, y, z, co = 0, cu = 0;
  cin >> a >> b >> c >> x >> y >> z;
  int A[3] = {a - x, b - y, c - z};
  for (int i = 0; i < 3; ++i) {
    if (A[i] < 0)
      co += A[i];
    else
      cu += A[i] / 2;
  }
  cout << (cu + co < 0 ? "No" : "Yes");
  return 0;
}
