#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>
using namespace std;


int main() {
    int n;cin >> n ;
    string s; cin >>s;
    int d=0;
    int l=0;
    int u=0;
    int sp=0;
    for(int i=0;i<n;i++)
    {
        if(s[i] >= '0' && s[i]<='9')
           d++;
        else if(s[i] >= 'a' && s[i]<='z')
            l++;
        else if(s[i] >= 'A' && s[i]<='Z')
            u++;
        else
            sp++;    
    }
    int c =0;
    if(l<1)
        c++;
    if(d<1)
        c++;
    if(u<1)
        c++;
    if(sp<1)
        c++;
    cout << max(c,((6)-n)) << endl;
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    return 0;
}