// Bismillahirohmanirohiim
#include<bits/stdc++.h>
using namespace std;

#define ios ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
#define mod %1000000007
#define moz 1000000007
#define nl "\n"
#define S second
#define F first
#define PB push_back
#define MP make_pair
#define V vector
#define P pair
#define LEN length()
#define SZ size()
#define fop(i,a,b) for(int (i)=(a);(i)<=(b);(i)++)
typedef long long ll;
//typedef complex<ll> C;
//#define X real()
//#define Y imag()
//const double EPS = 1e-9 ;
char uniq[12]={'!','@','#','$','%','^','&','*','(',')','-','+'};
int main()
{
    ios;
    int ans=0;
    int n;
    string s;
    cin >> n ;
    cin >> s ;
    if(n<6)
    {
        ans=6-n;
    }
    bool kecil=0;
    bool besar=0;
    bool digit=0;
    bool unik=0;
    fop(i,0,n-1)
    {
        if(s[i]>=65 && s[i]<=90) besar=1;
        if(s[i]>=97 && s[i]<=122) kecil=1;
        if(s[i]>=48 && s[i]<=57) digit=1;
        if(!unik)
            fop(j,0,11)
            {
                if(s[i]==uniq[j]) unik=1;
            }
    }
    if(ans>0)
    {
        int x=0;
        if(!besar) x++;
        if(!kecil) x++;
        if(!unik) x++;
        if(!digit) x++;
        if(x>ans)
        {
            ans=x;
        }
    }
    else
    {
        if(!digit) ans++;
        if(!besar) ans++;
        if(!kecil) ans++;
        if(!unik) ans++;
    }
    cout << ans << nl;
}