#include <bits/stdc++.h>
int main() {
  int a, b, c, x, y, z, tot = 0;
  scanf("%d %d %d %d %d %d", &a, &b, &c, &x, &y, &z);
  if (a >= x)
    tot += (a - x) >> 1, a -= x, x = 0;
  else
    x -= a;
  if (b >= y)
    tot += (b - y) >> 1, b -= y, y = 0;
  else
    y -= b;
  if (c >= z)
    tot += (c - z) >> 1, c -= z, z = 0;
  else
    z -= c;
  if (tot >= x + y + z)
    printf("Yes\n");
  else
    printf("No\n");
  return 0;
}
