#include <bits/stdc++.h>
using namespace std;
long long a, b, c, x, y, z;
long long rem, ex;
bool flag = 1;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cin >> a >> b >> c;
  cin >> x >> y >> z;
  if (a > x) ex = (a - x) / 2;
  if (b > y) ex += (b - y) / 2;
  if (c > z) ex += (c - z) / 2;
  if (a < x) {
    rem = x - a;
    if (ex < rem) flag = 0;
    ex -= rem;
  }
  if (b < y) {
    rem = y - b;
    if (ex < rem) flag = 0;
    ex -= rem;
  }
  if (c < z) {
    rem = z - c;
    if (ex < rem) flag = 0;
    ex -= rem;
  }
  if (flag)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
  return 0;
}
