#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


//numbers = "0123456789"
//lower_case = "abcdefghijklmnopqrstuvwxyz"
//upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
//special_characters = "!@#$%^&*()-+"
int main() {
    int n;
    string s;
    cin >> n >> s;
  
    
    auto  special_characters = "!@#$%^&*()-+"s;
        
    bool has_number = false;
    bool has_lowercase = false;
    bool has_uppercase = false;
    bool has_special = false;
    for( auto c: s ) {
        if( c >= 'a' && c <= 'z' ) has_lowercase = true;
        if( c >= 'A' && c <= 'Z' ) has_uppercase = true;
        if( c >= '0' && c <= '9' ) has_number = true;
        if( special_characters.find(c) != string::npos ) has_special = true;         
    }
        
    int m = 0;
    if( !has_lowercase ) ++m;
    if( !has_uppercase ) ++m;        
    if( !has_number ) ++m;                
    if( !has_special ) ++m;                        
    if( s.length() >= 6 ) {
        cout << m;
    }
    else {
        cout << max(6 - (int)s.length(), m);
    }
}