#include <bits/stdc++.h>
using namespace std;
const double PI = acos(-1);
int a, b, c;
int x, y, z;
int main() {
  cin >> a >> b >> c;
  cin >> x >> y >> z;
  int sum1 = 0, sum2 = 0;
  if (a > x)
    sum1 += (a - x) / 2;
  else
    sum2 += (x - a);
  if (b > y)
    sum1 += (b - y) / 2;
  else
    sum2 += (y - b);
  if (c > z)
    sum1 += (c - z) / 2;
  else
    sum2 += (z - c);
  if (sum1 >= sum2)
    puts("Yes");
  else
    puts("No");
}
