#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int a, b, c, x, y, z;
  cin >> a >> b >> c >> x >> y >> z;
  bool g = false;
  long long int dif1, dif2, dif3;
  dif1 = a - x;
  dif2 = b - y;
  dif3 = c - z;
  if (dif1 >= 0 && dif2 >= 0 && dif3 >= 0)
    g = true;
  else {
    long long int pos = 0;
    long long int neg = 0;
    if (dif1 >= 0)
      pos += dif1 / 2;
    else
      neg += (-1 * dif1);
    if (dif2 >= 0)
      pos += dif2 / 2;
    else
      neg += (-1 * dif2);
    if (dif3 >= 0)
      pos += dif3 / 2;
    else
      neg += (-1 * dif3);
    if (pos >= neg) g = true;
  }
  if (g)
    cout << "Yes\n";
  else
    cout << "No\n";
}
