#include <bits/stdc++.h>
using namespace std;
int main() {
  int a[3], x[3];
  for (int i = 0; i < 3; ++i) cin >> a[i];
  for (int i = 0; i < 3; ++i) cin >> x[i];
  int cnt1 = 0, cnt2 = 0;
  for (int i = 0; i < 3; ++i) {
    if (a[i] > x[i])
      cnt1 += (a[i] - x[i]) / 2;
    else
      cnt2 += x[i] - a[i];
  }
  if (cnt1 >= cnt2)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
  return 0;
}
