#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c;
  cin >> a >> b >> c;
  int x, y, z;
  cin >> x >> y >> z;
  int a_rest = 0, a_sh = 0, b_rest = 0, b_sh = 0, c_sh = 0, c_rest = 0;
  if (a > x) {
    a_rest = a - x;
    if (a_rest % 2 == 1) a_rest--;
    a_sh = 0;
  } else {
    a_rest = 0;
    a_sh = x - a;
  }
  if (b > y) {
    b_rest = b - y;
    if (b_rest % 2 == 1) b_rest--;
    b_sh = 0;
  } else {
    b_rest = 0;
    b_sh = y - b;
  }
  if (c > z) {
    c_rest = c - z;
    if (c_rest % 2 == 1) c_rest--;
    c_sh = 0;
  } else {
    c_rest = 0;
    c_sh = z - c;
  }
  int free_pair = (a_rest + b_rest + c_rest) / 2;
  int need = a_sh + b_sh + c_sh;
  if (free_pair >= need)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
  return 0;
}
