#include <bits/stdc++.h>
using namespace std;
int main() {
  int O[3], A[3], need = 0, have = 0;
  for (__typeof(3) i = 0 - (0 > 3); i != 3 - (0 > 3); i += 1 - 2 * (0 > 3))
    cin >> O[i];
  for (__typeof(3) i = 0 - (0 > 3); i != 3 - (0 > 3); i += 1 - 2 * (0 > 3))
    cin >> A[i];
  for (__typeof(3) i = 0 - (0 > 3); i != 3 - (0 > 3); i += 1 - 2 * (0 > 3)) {
    if (O[i] > A[i])
      have += (O[i] - A[i]) / 2;
    else if (A[i] > O[i])
      need += (A[i] - O[i]);
  }
  if (have >= need)
    printf("Yes\n");
  else
    printf("No\n");
  return 0;
}
