#include <bits/stdc++.h>
using namespace std;
long long int a[100009], b[100009];
int main() {
  long long int i, j, k, l, m, n, flag, count, sum, ans, t, A, B, C, D, x, y, z,
      diff, count2, count3;
  vector<long long int> v;
  cin >> A >> B >> C;
  cin >> x >> y >> z;
  sum = 0, count = 0, diff = 0;
  if (A >= x)
    count = (A - x) / 2, sum += count;
  else
    count = x - A, diff += count;
  if (B >= y)
    count = (B - y) / 2, sum += count;
  else
    count = y - B, diff += count;
  if (C >= z)
    count = (C - z) / 2, sum += count;
  else
    count = z - C, diff += count;
  if (sum >= diff)
    cout << "Yes\n";
  else
    cout << "No\n";
  return 0;
}
