var n,i,p: integer;
begin
readln(n);
p:=1;
i:=0;
repeat
i:=i+1;
p:=p*2*i;
until i=n;
writeln(p);
end.
var n,i,p: integer;
begin
readln(n);
p:=1;
i:=0;
repeat
i:=i+1;
p:=p*2*i;
until i=n;
writeln(p);
end.