#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string s) {
  int c=0,l=0,i,ll=0,ul=0,d=0,sp=0;
    for(i=0;i<n;i++){
        if(s[i]>='a' && s[i]<='z') ll=1;
                if(s[i]>='A' && s[i]<='Z') ul=1;
                if(s[i]>='0' && s[i]<='9') d=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]=='+') sp=1;
        
    }
    if(d==0) c++;
        if(ul==0) c++;
        if(ll==0) c++;
        if(sp==0) c++;
    return max(6-n,c);
    
}

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