#include <bits/stdc++.h>
#include <stdlib.h>

using namespace std;

typedef long long int ll;
typedef long double ld;

#define rep(i,a,b) for(ll i=a;i<=b;++i)
#define rev(i,a,b) for(ll i=a;i>=b;i--)
#define pll pair<ll,ll>
#define vll vector<ll>
#define sll set<ll>
#define vpll vector<pll>
#define F first
#define S second
#define pb push_back
#define mp make_pair
#define ln length()
#define M 1000000007
const string numbers = "0123456789";
const string lower_case = "abcdefghijklmnopqrstuvwxyz";
const string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const string special_characters = "!@#$%^&*()-+";
int main()
{
    ios::sync_with_stdio(false);cin.tie(0);
    ll n;cin>>n;
    string s;cin>>s;
    ll ans=0;
    ll ct=4;
    bool done=0;
    for(char ch:numbers){
        for(char cc:s) if(cc == ch){
            ct--;done=1;
            break;
        }
        if(done) break;
    }
    done=0;
    for(char ch:lower_case){
        for(char cc:s) if(cc == ch){
            ct--;done=1;
            break;
        }
        if(done) break;
    }
    done=0;
    for(char ch:upper_case){
        for(char cc:s) if(cc == ch){
            ct--;done=1;
            break;
        }
        if(done) break;
    }
    done=0;
    for(char ch:special_characters){
        for(char cc:s) if(cc == ch){
            ct--;done=1;
            break;
        }
        if(done) break;
    }
    ll ext=max(0LL,6LL-(ll)s.size());
    cout<<max(ext,ct)<<'\n';
}