#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 i,j=0,a=0,b=0,c=0,d=0,e=0;
    for(i=0;i<n;i++){
        if(p[i]>='0' && p[i]<='9'){
            a=1;
        }
        else if(p[i]>='a' && p[i]<='z'){
            b=1;
        }
        else if(p[i]>='A' && p[i]<='Z'){
            c=1;
        }
        else 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){
        j++;
    }
    if(!b){
        j++;
    }
    if(!c){
        j++;
    }
    if(!d){
        j++;
    }
    if(p.size()+j<6){
        j+=(6-(p.size()+j));
    }
    return j;
}

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