Codeigo 2020

help
1

Can anyone explain how to dirve formula for CodeChef: Practical coding for everyone

I come to know
f(n,m) ={
ncm ,m>1 and pow(3,n) for m=1;

}

but it seems than mine f(n,m) is wrong ,can anyone helps???

2

Check this :point_up:

3

okay thanks brother