#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>


int main() {
    std::string numbers = "0123456789";
    std::string lower_case = "abcdefghijklmnopqrstuvwxyz";
    std::string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    std::string special_characters = "!@#$%^&*()-+";
  
  bool nms = false;
  bool lcs = false;
  bool ucs = false;
  bool scs = false;
  
  int n;
  std::cin >> n;
  std::string pass;
  std::cin >> pass;
  
  for(int i = 0; i < n; ++i) {
    
    for (int j = 0; j < numbers.size() && !nms; ++j) {
      if (pass[i] == numbers[j]) {
        nms = true;
      }
    }
    
    for (int j = 0; j < lower_case.size() && !lcs; ++j) {
      if (pass[i] == lower_case[j]) {
        lcs = true;
      }
    }
    
    for (int j = 0; j < upper_case.size() && !ucs; ++j) {
      if (pass[i] == upper_case[j]) {
        ucs = true;
      }
    }
    
    for (int j = 0; j < special_characters.size() && !scs; ++j) {
      if (pass[i] == special_characters[j]) {
        scs = true;
      }
    }
  }
  
  int sol = 0;
  
  if (!nms) {
    ++sol;
  }
  if (!lcs) {
    ++sol;
  }
  if (!ucs) {
    ++sol;
  }
  if (!scs) {
    ++sol;
  }
  
  if (n + sol < 6) {
    sol += (6 - (n + sol));
  }
  
  
  std::cout << sol << std::endl;
  
  return 0;
}