#include <bits/stdc++.h>
#define mp make_pair
#define f first
#define s second


using namespace std;

int n;

string S;

string key = "!@#$%^&*()-+";
int ans = 0;


int main()
{
    ios_base::sync_with_stdio(0);
    //freopen("inp.txt", "r", stdin);
    cin >> n >> S;
    int f1 = 0, f2 = 0, f3 = 0, f4 = 0;

    for(int i=0; i<S.size(); i++){
        if(S[i] >= '0' && S[i] <= '9' && f1 == 0){
            ans++;
            f1 = 1;
        }
        if(S[i] >= 'a' && S[i] <= 'z' && f2 == 0){
            ans++;
            f2 = 1;
        }
        if(S[i] >= 'A' && S[i] <= 'Z' && f3 == 0){
            ans++;
            f3 = 1;
        }
        for(int j=0; j<key.size(); j++)
            if(S[i] == key[j] && f4 == 0){
                ans++;
                f4 = 1;
                break;
            }
    }
    ans = max(4-ans, 6-(int)S.size());

    cout << ans;
}