#include <bits/stdc++.h>
using namespace std;
int a, b, c, x, y, z;
int main() {
  while (~scanf("%d%d%d%d%d%d", &a, &b, &c, &x, &y, &z)) {
    int res1 = 0, res2 = 0;
    if (a > x)
      res1 += (a - x) / 2;
    else
      res2 += x - a;
    if (b > y)
      res1 += (b - y) / 2;
    else
      res2 += y - b;
    if (c > z)
      res1 += (c - z) / 2;
    else
      res2 += z - c;
    if (res1 >= res2)
      printf("Yes\n");
    else
      printf("No\n");
  }
  return 0;
}
