#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
    int fs=0,fla=0,fd=0,fsp=0,ans=0;
    for(int i=0;i<n;i++)
    {
        if(password[i]>=65 && password[i]<=90)
            fs=1;
        if(password[i]>=97 && password[i]<=122)
            fla=1;
        if(password[i]>=48 && password[i]<=57)
            fd=1;
        if(password[i]=='!' ||password[i]=='@' ||password[i]=='#' ||password[i]=='$' ||password[i]=='%' ||password[i]=='^' ||password[i]=='&' ||password[i]=='*' ||password[i]=='(' ||password[i]==')' ||password[i]=='-' ||password[i]=='+')
            fsp=1;
    }
    if(fs==0)
        ans++;
    if(fla==0)
        ans++;
    if(fd==0)
        ans++;
    if(fsp==0)
        ans++;
    ans=(ans>=(6-n))?ans:(6-n);
    return ans;
    
    // Return the minimum number of characters to make the password strong
}

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