/*    
 *  eat_code    
 *  IIIT Allahabad
 */
#include <bits/stdc++.h>
//#include "pretty_print.h"
using namespace std;

#define mp make_pair
#define mt make_tuple
#define pb push_back
#define CONTAINS(a, x) (a.find(x) != a.end())
#define ALL(x) x.begin(), x.end()
#define SZ(x) (int)x.size()
#define nl cout << endl
#define F first
#define S second

#define what_is(x) cout << #x << " = " << x << endl
#define boost ios::sync_with_stdio(false);cin.tie(NULL)
#define CASET int ___T, case_n = 1; cin >> ___T; while (___T-- > 0) 


#define rep(it, st, en) for(ll it = st; it < en; it++)
#define rep1(it, st, en) for(ll it = st; it <= en; it++)
#define per(it, st, en) for(ll it = en - 1; it >= st; it--)

typedef long long ll;
typedef pair<int, int> ii;
typedef pair<ll,ll> pll;

typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<bool> vb;
typedef vector<ii> vii;
typedef vector<vi> vvi;

ll INF = 1E9;
ll M = 1E9 + 7;

inline ll power (ll a,ll p){
    ll res = 1, x = a;
    while ( p ) {
        if ( p & 1 ) res = ( res * x );
        x = ( x * x ); p >>= 1;
    }
    return res;
}

template <typename T> ostream& operator<<(ostream& os, const vector<T> &p){os << "[ "; for (T x: p) os << x << " "; os << "]" << endl; return os;}
template <typename T> ostream& operator<<(ostream& os, const set<T> &p){os << "{ "; for (T x: p) os << x << " "; os << "}" << endl; return os;}
template <typename Tk, typename Tv> ostream& operator<<(ostream& os, const map<Tk, Tv> &p){os << "{ "; for (pair<Tk, Tv> x: p) os << x << " "; os << "}" << endl; return os;}
template <typename Tk, typename Tv> ostream& operator<<(ostream& os, const pair<Tk, Tv> &p){os << "{" << p.first << ',' << p.second << "}";return os;}

int main() {
    boost;
    if(fopen("input.txt", "r")){
      freopen("input.txt", "r", stdin);
      freopen("output.txt", "w", stdout);
    }
    int n;
    cin >> n;
    string s;
    cin >> s;
    string numbers = "0123456789";
    string lower_case = "abcdefghijklmnopqrstuvwxyz";
    string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    string special_characters = "!@#$%^&*()-+";
    vector<string> v;
    v.pb(numbers);
    v.pb(lower_case);
    v.pb(upper_case);
    v.pb(special_characters);
    vi cnt(4, 0);
    rep(i, 0, n){
        char c = s[i];
        rep(j, 0, SZ(v)){
            rep(k, 0, SZ(v[j])){
                if(v[j][k] == c)
                    cnt[j]++;
            }
        }
    }
    ll ans = 0;
    rep(i, 0, SZ(v))
        if(cnt[i] == 0)
            ans++;
    if((SZ(s) + ans) < 6)
        ans += (6 - (SZ(s) + ans));
    cout << ans << "\n";

    return 0;
}
//  Train Insane or Remain the same