#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  int ha, hb, hc, ra, rb, rc, ex, re;
  cin >> ha >> hb >> hc;
  cin >> ra >> rb >> rc;
  ex = re = 0;
  if (ha >= ra)
    ex += (ha - ra) / 2;
  else
    re += (ra - ha);
  if (hb >= rb)
    ex += (hb - rb) / 2;
  else
    re += (rb - hb);
  if (hc >= rc)
    ex += (hc - rc) / 2;
  else
    re += (rc - hc);
  if (ex < re)
    cout << "No\n";
  else
    cout << "Yes\n";
  return 0;
}
