Fleiss Kappa score - NaN for perfect agreement

I am working on a dataset that has three raters. Rating are Yes/No. I have a set of ratings where all raters said No. I used a R package and excel formulas to calculate the kappa score. Both return NaN. I get why it returns NaN. Because the expected probability is 1, the denominator is 0. Hence the NaN. It seems the case is valid when all raters mention Yes to all instances.

Isn't this a perfect agreement?

Here is the data to reproduce

#    Rater 1    Rater 2    Rater 3    Yes    No
1        Yes        Yes        Yes      3     0
2        Yes        Yes        Yes      3     0
3        Yes        Yes        Yes      3     0
4        Yes        Yes        Yes      3     0
5        Yes        Yes        Yes      3     0
6        Yes        Yes        Yes      3     0

Pe = (sum(Yes)/N*n)^2 + (sum(No)/N*n)^2
= 18/6*3 + 0/6*3
= 1

Po = 1/(N*n*(n-10)*(Sum_of_squares(all_ratings) - N*n)
= 1/(6*3*2) * ((3^2+3^2+...+0^2+0^2)-6*3)
= 1/36 * (54-18)
= 1/36 * 36
= 1

kappa = Po - Pe / 1 - Pe
= 1 - 1 / 1 - 1
= NaN