#include <bits/stdc++.h>
using namespace std;
int a[10], b[10];
int i, cnt, low;
int main() {
  for (i = 1; i <= 3; i++) scanf("%d", &a[i]);
  for (i = 1; i <= 3; i++) {
    scanf("%d", &b[i]);
    a[i] -= b[i];
    if (a[i] > 0)
      cnt += a[i] / 2;
    else
      low += a[i];
  }
  if (cnt + low >= 0)
    printf("Yes\n");
  else
    printf("No\n");
  return 0;
}
