#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c;
  int x, y, z;
  scanf("%d", &(a));
  scanf("%d", &(b));
  scanf("%d", &(c));
  scanf("%d", &(x));
  scanf("%d", &(y));
  scanf("%d", &(z));
  int need = max(0, x - a) + max(0, y - b) + max(0, z - c);
  int left = max(0, a - x) / 2 + max(0, b - y) / 2 + max(0, c - z) / 2;
  if (need <= left) {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
  return 0;
}
