#include <bits/stdc++.h>
using namespace std;
int v[5], d[5];
int has, need;
int main() {
  scanf("%d %d %d", &v[0], &v[1], &v[2]);
  scanf("%d %d %d", &d[0], &d[1], &d[2]);
  for (int i = 0; i < 3; i++) {
    int dif = v[i] - d[i];
    if (dif > 0)
      has += dif / 2;
    else
      need -= dif;
  }
  if (has >= need)
    printf("Yes\n");
  else
    printf("No\n");
}
