#include <bits/stdc++.h>
using namespace std;
int main() {
  int a[3], b[3];
  for (int i = 0; i < 3; i++) cin >> a[i];
  for (int i = 0; i < 3; i++) cin >> b[i];
  int can = 0;
  for (int i = 0; i < 3; i++) can += max(a[i] - b[i], 0) / 2;
  int req = 0;
  for (int i = 0; i < 3; i++) req += max(b[i] - a[i], 0);
  if (can >= req)
    cout << "Yes\n";
  else
    cout << "No\n";
}
