#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string p) {
    // Return the minimum number of characters to make the password strong
    int a=0,b=0,c=0,d=0,e=n;
    for(int i=0;i<n;i++)
    {
        if(p[i]>=65 && p[i]<=90)
        {
            a=1;
        }
        if(p[i]>=97 && p[123]<=122)
        {
            b=1;
        }
        if(p[i]>=48 && p[i]<=57)
        {
            c=1;
        }
        if(p[i]=='!' || p[i]=='@' || p[i]=='#' ||p[i]=='$' ||p[i]=='%' ||p[i]=='^' ||p[i]=='&' ||p[i]=='*' ||p[i]=='(' ||p[i]=='+' ||p[i]=='-' ||p[i]==')')
        {
            d=1;
        }
    }
    if(a==0)
        n++;
    if(b==0)
        n++;
    if(c==0)
        n++;
    if(d==0)
        n++;
    if(n<6)
        n=6;
        return n-e;
}

int main() {
    int n;
    cin >> n;
    string password;
    cin >> password;
    int answer = minimumNumber(n, password);
    cout << answer << endl;
    return 0;
}