#include <bits/stdc++.h>
int main() {
  long long t, s1, s2, i, j, max, a, b, c, x, y, z;
  scanf("%I64d%I64d%I64d%I64d%I64d%I64d", &a, &b, &c, &x, &y, &z);
  s1 = 0;
  s2 = 0;
  if (a - x > 0)
    s1 += (a - x) / 2;
  else
    s2 += x - a;
  if (b - y > 0)
    s1 += (b - y) / 2;
  else
    s2 += y - b;
  if (c - z > 0)
    s1 += (c - z) / 2;
  else
    s2 += z - c;
  if (s1 >= s2)
    printf("Yes");
  else
    printf("No");
  return 0;
}
