#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int h1, h2, h3, r1, r2, r3, nt, pt, dt;
  dt = 0;
  pt = 0;
  scanf("%lld", &h1);
  scanf("%lld", &h2);
  scanf("%lld", &h3);
  scanf("%lld", &r1);
  scanf("%lld", &r2);
  scanf("%lld", &r3);
  if (r1 > h1)
    dt += (r1 - h1);
  else
    pt += (h1 - r1) / 2;
  if (r2 > h2)
    dt += (r2 - h2);
  else
    pt += (h2 - r2) / 2;
  if (r3 > h3)
    dt += (r3 - h3);
  else
    pt += (h3 - r3) / 2;
  if (pt >= dt)
    printf("Yes\n");
  else
    printf("No\n");
  return 0;
}
