#include <bits/stdc++.h>

using namespace std;


int main() {
    int n;
    cin >> n;
    string s;
    cin >> s;
    int digi=0;
    int special=0;
    int low=0;
    int high=0;
    for(int i=0;i<n;i++)
    {
        if(s[i]>='A'&&s[i]<='Z')
            high++;
        else if(s[i]>='a'&&s[i]<='z')
            low++;
        else if(s[i]>='0'&&s[i]<='9')
            digi++;
        else
            special++;
    }
    int cnt=0;
    if(high==0)
        cnt++;
    if(low==0)
        cnt++;
    if(digi==0)
        cnt++;
    if(special==0)
        cnt++;
    int ans;
    if(n<6)
    {
        ans=max(6-n,cnt);
    }
    else
        ans=cnt;

    cout << ans << endl;
    return 0;
}