#include <bits/stdc++.h>
int main() {
  long a, b, c, x, y, z, extra, need, d, e;
  while (scanf(" %ld %ld %ld %ld %ld %ld", &a, &b, &c, &x, &y, &z) == 6) {
    need = 0, extra = 0;
    if (a >= x)
      e = a - x;
    else {
      d = x - a;
      need += d;
      e = 0;
    }
    extra += e / 2;
    if (b >= y)
      e = b - y;
    else {
      d = y - b;
      need += d;
      e = 0;
    }
    extra += e / 2;
    if (c >= z)
      e = c - z;
    else {
      d = z - c;
      need += d;
      e = 0;
    }
    extra += e / 2;
    if (extra >= need)
      printf("Yes\n");
    else
      printf("No\n");
  }
  return 0;
}
