#include <iostream>
#include <climits>
#include <cmath>
#include <cstring>
#include <cctype>
#include <cstdio>
#include <cstdlib>
#include <iomanip>
#include <utility>
#include <sstream>
#include <algorithm>
#include <stack>
#include <set>
#include <list>
#include <map>
#include <unordered_map>
#include <queue>
#include <deque>
#include <vector>
#include <stdint.h> //uint32_t
#include <functional>
#include <bitset>

using namespace std;

typedef long long           ll;
typedef double              lf;
typedef unsigned long long  ull;
typedef pair<int, int>      pii;
typedef vector<pii>         vpii;
typedef vector<int>         vi;

#define __FastIO        ios_base::sync_with_stdio(false); cin.tie(0)

#define forr(i, a, b)   for (__typeof (a) i=a; i<=b; i++)
#define rof(i, b, a)    for (__typeof (a) i=b; i>=a; i--)
#define rep(i, n)       for (__typeof (n) i=0; i<n; i++)
#define forit(i, s)     for (__typeof ((s).end ()) i = (s).begin (); i != (s).end (); ++i)
#define all(ar)         ar.begin(), ar.end()
#define fill(ar, val)   memset(ar, val, sizeof(ar))
#define clr(a)          memset(a, 0, sizeof(a))

#define nl              cout << '\n';
#define sp              cout << ' ';
#define ckk             cout << "##########\n"
#define pb              push_back
#define debug1(x)       cerr << #x << ": " << x << endl
#define debug2(x, y)    cerr << #x << ": " << x << '\t' << #y << ": " << y << endl
#define debug3(x, y, z) cerr << #x << ": " << x << '\t' << #y << ": " << y << '\t' << #z << ": " << z << endl

#define PI              acos(-1.0)
#define INF             0x7fffffff
#define MOD             1000000007
#define EPS             1e-7
#define MAX             10000005

////////////////////////// START HERE //////////////////////////


int main() {
    __FastIO;
    int n, len = 0, digit = 0, lo = 0, up = 0, spc = 0;
    string str;
    string special_characters = "!@#$%^&*()-+";
    cin >> n >> str;
    len = (int) str.size();
    forit(i, str) {
        if (isdigit(*i)) digit++;
        else if (*i >= 'a' and * i <= 'z') lo++;
        else if (*i >= 'A' and * i <= 'Z') up++;
        else if (special_characters.find(*i) != string::npos) spc++;
    }
    int cnt = 0;
    if (digit) cnt++;
    if (lo) cnt++;
    if (up) cnt++;
    if (spc) cnt++;
    cnt = 4 - cnt;
    cnt = max(6 - len, cnt);
    cout << cnt << endl;
    return 0;
}