Dear,

 

there should be some condition in n and m .

 

otherwise it will be  a lot of possibilities to fulfill the condition.

 

1) only one person sits in first and rest  m-1 sits in 2 row.

2) two person sit in first and rest m-2 sits in 2nd row.

3) three person sit in first and rest m-3 sits in 2nd row.

............and so on.

 

hence please clear the relation between m and n.