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