Answer:
hello your question is incomplete attached below is a the complete question
answer : n = 5
Explanation:
lets consider N to be 5
To prove that the least number 'n' = 5
we will represent this information in a graph as vertex
Black edge = Friends
Blue edge = not Friends
From the attached diagram any vertex contains 0,1,2,3,4 black lines and 4,3,2,1,0 blue lines
attached below is an explanation related to the choice of n = 5
considering n = 5 is satisfied by the explanation given