#include <bits/stdc++.h>
using namespace std;
int main() {
  int snum1, snum2, snum3;
  int enum1, enum2, enum3;
  cin >> snum1 >> snum2 >> snum3 >> enum1 >> enum2 >> enum3;
  int count = 0;
  count += snum1 >= enum1 ? (snum1 - enum1) / 2 : snum1 - enum1;
  count += snum2 >= enum2 ? (snum2 - enum2) / 2 : snum2 - enum2;
  count += snum3 >= enum3 ? (snum3 - enum3) / 2 : snum3 - enum3;
  if (count < 0) {
    cout << "No" << endl;
    return 0;
  }
  cout << "Yes" << endl;
  return 0;
}
