#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string p) {
 int count=0,cap=0,low=0,dig=0,special=0;
    int num;
    for(int i=0;i<n;i++)
    {if(isupper(p[i])) cap++;
     if(islower(p[i])) low++;
     if(isdigit(p[i])) dig++;
   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]==+'+')
       special++;
    }
    int req=0;
    if(special==0)
    req++;
    if(cap==0)
    req++;
    if(low==0) req++;
    if(dig==0) req++;
    if(n<6){
    if(req<(6-n)) 
     return 6-n;
    }
    return req;
}

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