/*Template by hemnath_d(Enlightened by chamow)*/
#include<bits/stdc++.h>
using namespace std;
/*--------------------------------------------------------------*/
typedef long long ll;
typedef long double ld;
typedef vector<ll> vec;
typedef vector<int> vi;
typedef pair<ll,ll> pll;
typedef pair<int,int> pii;
/*--------------------------------------------------------------*/
#define fastread ios_base::sync_with_stdio(false); cin.tie(NULL);
#define pb push_back
#define mp make_pair
#define fx first
#define sx second
#define forw(i,a,n) for(i=a;i<=n;i++)
#define rev(i,a,n) for(i=a;i>=n;i--)
#define For(i,a,n) for(i=a;i<n;i++)
#define Rev(i,a,n) for(i=a;i>n;i--)
#define inf 100000000000000
#define minf -100000000000000
/*--------------------------------------------------------------*/
//Function to add an edge for graph
//Undirected graph
void add_edge(vec adj[],ll a,ll b)
{
    adj[a].pb(b);
    adj[b].pb(a);
}
/*---------------------------------------------------------------*/
//Comparator class for min-heap using priority_queue
//Change the parameters before use
class myComparator
{
public:
    int operator() (/*Datatype*/int p1,/*Datatype*/int  p2)
    {
        return p1/*value*/ > p2/*value*/;
    }
};
/*----------------------------------------------------------------*/
//END OF TEMPLATE
/*----------------------------------------------------------------*/
string a="abcdefghijklmnopqrstuvwxyz";
string b="ABCDEFGHIJKLMNOPQRSTUVWXYZ";
string c="!@#$%^&*()-+";
string d="0123456789";
int main()
{
    fastread;
    ll n;
    cin>>n;
    string s;
    cin>>s;
    ll i;
    ll ca=0,cb=0,cc=0,cd=0;
    For(i,0,n)
    {
        ll j;
        For(j,0,a.size())
        if(s[i]==a[j])
            ca++;
        For(j,0,b.size())
        if(s[i]==b[j])
            cb++;
        For(j,0,c.size())
        if(s[i]==c[j])
            cc++;
        For(j,0,d.size())
        if(s[i]==d[j])
            cd++;

    }
    ll regdig=6-s.size();
    if(s.size()>=6)
        regdig=minf;
    ll k=0;
    if(ca==0)
        k++;
    if(cb==0)
        k++;
    if(cc==0)
        k++;
    if(cd==0)
        k++;
    regdig=max(k,regdig);
    cout<<regdig<<endl;
    return 0;
}