program waterfire;
const
fin='circlex.in';
fout='circlex.out';
var
i,n,j:longint;
f,g:text;
a:array[0..1000] of longint;
begin
assign(f,fin);reset(f);
assign(g,fout);rewrite(g);
read(f,n);
 fillchar(a,sizeof(a),0);
 a[0]:=1;
 a[1]:=1;
 for i:=2 to n do    begin
  for j:=0 to i-2 do
   a[i]:=a[i]+a[j]*a[i-2-j];
   a[i]:=a[i]+a[i-1];  end;
write(g,a[n]);
close(g);
end.