I've a dataset like;
Height Patid
. 1
56 1
56 1
56 1
56 1
56 2
45 2
45 2
45 2
45 2
45 3
So How can I retain missing value to no 56 and 56 is not included in Patid =2
And output dataset like

Height Patid
56 1
56 1
56 1
56 1
56 1
45 2
45 2
45 2
45 2
45 2

Please solve this one..