#include <bits/stdc++.h>
using namespace std;
int main(int argc, const char* argv[]) {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int a, b, c, x, y, z;
  int spa = 0, spb = 0, spc = 0;
  int req = 0;
  cin >> a >> b >> c;
  cin >> x >> y >> z;
  if (a > x)
    spa = a - x;
  else
    req += x - a;
  if (b > y)
    spb = b - y;
  else
    req += y - b;
  if (c > z)
    spc = c - z;
  else
    req += z - c;
  if (spa > 0) req = req - spa / 2;
  if (spb > 0) req = req - spb / 2;
  if (spc > 0) req = req - spc / 2;
  if (req <= 0)
    cout << "Yes";
  else
    cout << "No";
  return 0;
}
