i,j,s,n:longint;

a:array[0..200] of longint;

begin

readln(n);

a[0]:=1;

for i:=1 to n do

begin

for j:=1 to i do

begin

a[i]:=a[i-j]*a[j-1]+a[i];

end;

end;

writeln(a[n]);

end.