#include <bits/stdc++.h>
using namespace std;
int vec[3], des[3], diff[3], credit[3];
bool ok() {
  int ans = 0;
  for (int i = 0; i < 3; i++) ans += credit[i];
  if (ans >= 0) return true;
  return false;
}
int main() {
  for (int i = 0; i < 3; i++) scanf("%d", &vec[i]);
  for (int i = 0; i < 3; i++) scanf("%d", &des[i]);
  for (int i = 0; i < 3; i++) diff[i] = vec[i] - des[i];
  for (int i = 0; i < 3; i++) {
    if (diff[i] > 0)
      credit[i] = diff[i] / 2;
    else
      credit[i] = diff[i];
  }
  if (ok())
    printf("Yes\n");
  else
    printf("No\n");
  return 0;
}
