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