#include <bits/stdc++.h>
using namespace std;
const int MAXN = 200005;
const int inf = 1000000007;
int main() {
  int a, b, c;
  int x, y, z;
  cin >> a >> b >> c;
  cin >> x >> y >> z;
  int da = a - x;
  int db = b - y;
  int dc = c - z;
  int can = max(0, da / 2) + max(0, db / 2) + max(0, dc / 2);
  int needed = min(0, da) + min(0, db) + min(0, dc);
  cout << (can + needed >= 0 ? "Yes" : "No") << endl;
  return 0;
}
