Pascal :

var
j,m,z:longint;
n,k,p,i:integer;
begin
 read(n,k,p);j:=1;m:=1;
 if (n=1)or(n=2) then begin writeln('1');exit;end;
 for i:=3 to n do
 begin
  z:=j;j:=j+m;m:=z;
  if j mod k=1 then j:=j-1;
 end;
writeln(j mod p);
end.