#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c;
  int d, e, f;
  cin >> a >> b >> c >> d >> e >> f;
  int need = max(0, d - a) + max(0, e - b) + max(0, f - c);
  int have = max(a - d, 0) / 2 + max(0, b - e) / 2 + max(0, c - f) / 2;
  if (have >= need) {
    cout << "Yes\n";
  } else {
    cout << "No\n";
  }
}
