#include <bits/stdc++.h>
using namespace std;
int main() {
  int a[50];
  int b[50];
  for (int i = 0; i < 3; i++) {
    cin >> a[i];
  }
  for (int i = 0; i < 3; i++) {
    cin >> b[i];
  }
  int sum1 = 0;
  int sum2 = 0;
  for (int i = 0; i < 3; i++) {
    if (a[i] >= b[i]) {
      sum1 += (a[i] - b[i]) / 2;
    } else
      sum2 += b[i] - a[i];
  }
  puts(sum1 >= sum2 ? "Yes" : "No");
  return 0;
}
