#include<bits/stdc++.h>
#define llong long long
#define _pair pair<llong, llong>
#define MP make_pair
#define x first
#define y second
using namespace std;
string s;
int main()
{
	ios::sync_with_stdio(0);
	int n; cin>>n;
    cin>>s;
    int rs1=max(0,6-n);
    int k1,k2,k3,k4;
    k1=k2=k3=k4=0;
    for (int i=0; i < n; i++){
        if (('a' <= s[i])&&(s[i] <= 'z'))
            k1=1;
        if (('A' <= s[i])&&(s[i] <= 'Z'))
            k2=1;
        if (('0' <= s[i])&&(s[i] <= '9'))
            k3=1;
        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] == '+'))
            k4=1;
    }
    cout<<max(rs1,4-k1-k2-k3-k4);
	return 0;
}