#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c;
  scanf("%d%d%d", &a, &b, &c);
  int x, y, z;
  scanf("%d%d%d", &x, &y, &z);
  int cnt = 0, cnt1 = 0;
  if (a >= x)
    cnt += (a - x) / 2;
  else
    cnt1 += x - a;
  if (b >= y)
    cnt += (b - y) / 2;
  else
    cnt1 += y - b;
  if (c >= z)
    cnt += (c - z) / 2;
  else
    cnt1 += z - c;
  if (cnt >= cnt1)
    printf("Yes\n");
  else
    printf("No\n");
  return 0;
}
