program ss;

var b:array[1..20] of integer;

i,j,n,s,k:longint;

procedure dfs(x,y:integer);

var i:integer;

begin

for i:=x+1 to y do

if y-i>x then dfs(i,y-i)

else begin s:=s+1; exit; end;

end;

begin

read(n); s:=0; k:=0;

dfs(0,n);

write(s-1);

end.