#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)
#define fore(i,a) for(auto &i:a)
#pragma GCC optimize ("-O3")
using namespace std; void _main(); int main() { cin.tie(0); ios::sync_with_stdio(false); _main(); }
//---------------------------------------------------------------------------------------------------


string S;
string numbers = "0123456789";
string lower_case = "abcdefghijklmnopqrstuvwxyz";
string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
string special_characters = "!@#$%^&*()-+";
//---------------------------------------------------------------------------------------------------
void _main() {
    int N; cin >> N;
    cin >> S;

    int ans = 0;
    int a = 0, b = 0, c = 0, d = 0;
    
    fore(cc, S) {
        if (numbers.find(cc) != string::npos) a = 1;
        if (lower_case.find(cc) != string::npos) b = 1;
        if (upper_case.find(cc) != string::npos) c = 1;
        if (special_characters.find(cc) != string::npos) d = 1;
    }

    if (!a) ans++;
    if (!b) ans++;
    if (!c) ans++;
    if (!d) ans++;

    //printf("%d %d %d %d\n", a, b, c, d);

    if (S.length() + ans < 6) ans = 6 - S.length();
    cout << ans << endl;
}