#include <bits/stdc++.h>
using namespace std;

#define REP(i, a, b) for(register int i = a; i < b; i++)
#define rep(i, b) REP(i, 0, b)
#define fast ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
#define test(t) int t; cin >> t; while(t--)
#define debug(i) cout << "debug : " << i << endl;
#define ll long long
#define pb push_back
#define mp make_pair
#define vi vector<int>
#define mod 1000000007

int main() {
    fast;
    
    int N, count = 0;
    string S;
    cin >> N >> S;
    bool dig = false, upp = false, low = false, special = false;
    for (char c : S) {
        if (isdigit(c)) {
            dig = true;
        } else if (isupper(c)) {
            upp = true;
        } else if (islower(c)) {
            low = true;
        } else {
            special = true;
        }
    }
    if (!dig)
        count++;
    if (!upp)
        count++;
    if (!low)
        count++;
    if (!special)
        count++;
    if (int(S.size()) >= 6) {
        count > 0 ? cout << count << endl : cout << 0 << endl;
    } else {
        if (count + int(S.size()) >= 6) {
            cout << count << endl;
        } else {
            cout << 6 - int(S.size()) << endl;
        }
    }
    return 0;
}