#include <bits/stdc++.h>
using namespace std;
int main() {
  long long a[3];
  cin >> a[0] >> a[1] >> a[2];
  long long b[3];
  cin >> b[0] >> b[1] >> b[2];
  long long cnt = 0;
  for (int i = 0; i < 3; i++) {
    if (a[i] >= b[i]) {
      cnt += (a[i] - b[i]) / 2;
    } else {
      cnt -= (b[i] - a[i]);
    }
  }
  if (cnt >= 0)
    cout << "Yes";
  else
    cout << "No";
  return 0;
}
