#include <iomanip>
#include <algorithm>
#include <numeric>
#include <fstream>
#include <iostream>
#include <iomanip>
#include <sstream>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <deque>
#include <list>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cctype>
#include <cmath>
#include <complex>
#include <cassert>
#include <bitset>
using namespace std;

int main(int argc, const char * argv[]) {
    string numbers = "0123456789";
    string lower_case = "abcdefghijklmnopqrstuvwxyz";
    string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    string special_characters = "!@#$%^&*()-+";
    int n;
    cin >> n;
    string s;
    cin >> s;
    int c1 = 0, c2 = 0, c3 = 0, c4 = 0;
    for (int i = 0; i < n; ++i) {
        if (c1 == 0)
        for (int j = 0; j < numbers.length(); ++j){
            if (s[i] == numbers[j]){
                c1=1;break;
            }
        }
        if (c2 == 0)
        for (int j = 0; j < lower_case.length(); ++j){
            if (s[i] == lower_case[j]){
                c2 = 1;break;
            }
        }
        if (c3 == 0)
        for (int j = 0; j < upper_case.length(); ++j){
            if (s[i] == upper_case[j]){
                c3 = 1;break;
            }
        }
        if (c4 == 0)
        for (int j = 0; j < special_characters.length(); ++j){
            if (s[i] == special_characters[j]){
                c4 = 1;break;
            }
        }
    }
    int cnt = c1+c2+c3+c4;
    int res = 4-cnt;
    if (n+res < 6)
        res+=6-(n+res);
    cout << res;
    return 0;
}