#include <string>
#include <vector>
#include <deque>
#include <iostream>
#include <cstdio>
#include <cstdlib>
using namespace std;

/* Test to see if a string s is a correct bracket sequence.
   Use a deque like a stack -- if a character is an opening
   character, push it on the stack.  If it is a closing character,
   check to see its opening character is on the stack.  If so, 
   pop it and continue.  Otherwise, return false. */

int is_cbs(string &s)
{
  deque <char> stack;
  int i;

  for (i = 0; i < s.size(); i++) {
    if (s[i] == '(' || s[i] == '[') {
      stack.push_front(s[i]);
    } else if (s[i] == ')' || s[i] == ']') {
      if (stack.empty() || (s[i] == ')' && stack[0] != '(') ||
                           (s[i] == ']' && stack[0] != '[')) return 0;
      stack.pop_front();
    } else return 0;
  }
  return stack.empty();
}

int main(int argc, char **argv)
{
  string s, tmp;
  int i, j, counter;

  if (argc != 2) { fprintf(stderr, "Usage a.out string\n"); exit(1); }
  s = argv[1];

  counter = 0;

  /* Generate all non-empty subsets of S and test them.  Count up the results. */

  for (i = 1; i < (1 << s.size()); i++) {
    tmp = "";
    for (j = 0; j < s.size(); j++) {
      if (i & (1 << j)) tmp.push_back(s[j]);
    }
    if (is_cbs(tmp)) counter++;
  }
  printf("%d\n", counter-1);
  exit(0);
}