#include <bits/stdc++.h>

using namespace std;

bool isspecial(char c) {
  for (char special: string("!@#$%^&*()-+")) {
    if (special == c) {
      return true;
    }
  }
  return false;
}

int minimumNumber(int n, string password) {
  int criterias[] = { 1, 1, 1, 1 };

  for (char c: password) {
    if (criterias[0] == 1 && islower(c)) {
      criterias[0] = 0;
    }
    if (criterias[1] == 1 && isupper(c)) {
      criterias[1] = 0;
    }
    if (criterias[2] == 1 && isdigit(c)) {
      criterias[2] = 0;
    }
    if (criterias[3] == 1 && isspecial(c)) {
      criterias[3] = 0;
    }
  }
  
  int missing = 0;
  for (int i = 0; i < sizeof(criterias)/sizeof(criterias[0]); i++) {
    missing += criterias[i];
  }

  int requiredLength = 6 - password.size();
  return max(requiredLength, missing);
}

int main() {
    int n;
    cin >> n;
    string password;
    cin >> password;
    int answer = minimumNumber(n, password);
    cout << answer << endl;
    return 0;
}