#include <bits/stdc++.h>
using namespace std;
int main() {
  int a[5], b[5], sum1 = 0, sum2 = 0;
  for (int i = 0; i < 3; i++) {
    cin >> a[i];
  }
  for (int i = 0; i < 3; i++) {
    cin >> b[i];
  }
  for (int i = 0; i < 3; i++) {
    if (b[i] < a[i])
      sum1 += (a[i] - b[i]) / 2;
    else
      sum2 += (b[i] - a[i]);
  }
  if (sum1 >= sum2)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
}
