#include <bits/stdc++.h>
using namespace std;
const int INF = 0x7f7f7f7f;
const int MAXN = 1e6 + 111;
int main() {
  int a, b, c, x, y, z;
  cin >> a >> b >> c >> x >> y >> z;
  int lefa = a - x, lefb = b - y, lefc = c - z;
  int sum = 0;
  if (lefa < 0) sum -= lefa, lefa = 0;
  if (lefb < 0) sum -= lefb, lefb = 0;
  if (lefc < 0) sum -= lefc, lefc = 0;
  int form = lefa / 2 + lefb / 2 + lefc / 2;
  if (form >= sum)
    cout << "Yes\n";
  else
    cout << "No\n";
  return 0;
}
