var
n,t0,i:longint;
d:array[0..100001]of char;
function check(l,r:longint):longint;
var x,tt0,z:longint;
begin
tt0:=1;
z:=l;
while z<=r do
 begin
  if d[z]='*'then tt0:=tt0*3;
  if d[z]='('then
   begin
    x:=n;
    while d[x]<>')'do dec(x);
    d[x]:=' ';
    tt0:=tt0*check(z+1,x-1);
    z:=x;
   end;
  inc(z);
 end;
check:=tt0;
end;

begin
assign(input,'exp.in');reset(input);
assign(output,'exp.out');rewrite(output);
readln(n);
for i:=1 to n do read(d[i]);
write(check(1,n));

close(input);
close(output);
end.