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