#include <bits/stdc++.h>
using namespace std;
void run() {
  int a, b, c;
  int x, y, z;
  cin >> a >> b >> c;
  cin >> x >> y >> z;
  int diff = max(0, x - a) + max(0, y - b) + max(0, z - c);
  int bonus = max(0, (a - x) / 2) + max(0, (b - y) / 2) + max(0, (c - z) / 2);
  bool p = (diff <= bonus);
  if (p)
    printf("Yes\n");
  else
    printf("No\n");
}
int main() {
  cout << fixed << setprecision(16);
  run();
  return 0;
}
