#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c, x, y, z, rem_x = 0, rem_y = 0, rem_z = 0, del_x = 0, del_y = 0,
                        del_z = 0, remender = 0, delay = 0;
  cin >> a >> b >> c;
  cin >> x >> y >> z;
  if (a > x) {
    rem_x = (a - x) / 2;
  } else {
    del_x = x - a;
  }
  if (b > y) {
    rem_y = (b - y) / 2;
  } else {
    del_y = y - b;
  }
  if (c > z) {
    rem_z = (c - z) / 2;
  } else {
    del_z = z - c;
  }
  remender = rem_x + rem_y + rem_z;
  delay = del_x + del_y + del_z;
  if (remender >= delay) {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
  return 0;
}
