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

#define boost ios::sync_with_stdio(false);cin.tie(NULL)
#define ll long long
#define ull unsigned long long
#define pll pair<ll,ll>
#define pb push_back
#define mp make_pair
#define fs first
#define sc second
const ll MOD=1E9+7;

int main()
{
    boost;

    ll i,n;
    cin>>n;

    string s;
    cin>>s;

    bool num=false;
    bool lcase=false;
    bool ucase=false;
    bool special=false;

    for (i=0;i<n;i++) {
    	if (s[i]>='a' && s[i]<='z')
    		lcase=true;
    	if (s[i]>='A' && s[i]<='Z')
    		ucase=true;
    	if (s[i]>='0' && s[i]<='9')
    		num=true;
    	if (s[i]=='!' || s[i]=='@' || s[i]=='#' || s[i]=='$' || s[i]=='%' || s[i]=='^' || s[i]=='&' || s[i]=='*' || s[i]=='(' || s[i]==')' || s[i]=='-' || s[i]=='+')
    		special=true;
    }

    ll req=0;
    if (!lcase)req++;
    if (!ucase)req++;
    if (!special)req++;
    if (!num)req++;

    if (n>=6 && req==0) {
    	cout<<0;
    }
    else {
    	ll sh=max(0LL,6-n);
    	cout<<max(req,sh);
    }

    return 0;
}