#include <bits/stdc++.h>
using namespace std;
pair<int, int> a[181];
int i, sum1, sum2;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  for (i = 1; i <= 3; i++) cin >> a[i].first;
  for (i = 1; i <= 3; i++) cin >> a[i].second;
  for (i = 1; i <= 3; i++)
    if (a[i].first > a[i].second)
      sum1 += (a[i].first - a[i].second) / 2;
    else
      sum2 += a[i].second - a[i].first;
  if (sum1 >= sum2)
    cout << "Yes" << '\n';
  else
    cout << "No" << '\n';
  return 0;
}
