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

bool isspecial(char c)
{
    static const char special[] = "!@#$%^&*()-+";
    return find(begin(special), end(special), c) != end(special);
}

int strong(const string& s)
{
    int need =
        !any_of(s.begin(), s.end(), isspecial)
        + !any_of(s.begin(), s.end(), [](char c) { return '0' <= c && c <= '9'; })
        + !any_of(s.begin(), s.end(), [](char c) { return 'a' <= c && c <= 'z'; })
        + !any_of(s.begin(), s.end(), [](char c) { return 'A' <= c && c <= 'Z'; });
    return max(6 - (int)s.length(), need);
}

int main() {
    string s; int n; cin >> n >> s;
    cout << strong(s) << endl;
    return 0;
}