#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c;
  cin >> a >> b >> c;
  int a_new, b_new, c_new;
  cin >> a_new >> b_new >> c_new;
  int a_res = 0, b_res = 0, c_res = 0;
  a_res = a - a_new;
  b_res = b - b_new;
  c_res = c - c_new;
  if (a_res > 0) a_res /= 2;
  if (b_res > 0) b_res /= 2;
  if (c_res > 0) c_res /= 2;
  int res = a_res + b_res + c_res;
  if (res < 0)
    cout << "No";
  else
    cout << "Yes";
  return 0;
}
