#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c;
  int x, y, z;
  scanf("%d%d%d", &a, &b, &c);
  scanf("%d%d%d", &x, &y, &z);
  int ret = 0;
  if (a > x)
    ret += (a - x) / 2;
  else
    ret += (a - x);
  if (b > y)
    ret += (b - y) / 2;
  else
    ret += (b - y);
  if (c > z)
    ret += (c - z) / 2;
  else
    ret += (c - z);
  if (ret >= 0)
    puts("Yes");
  else
    puts("No");
  return 0;
}
