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


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */ 
    int x,n,i,ans=0,digit=0,small=0,large=0,sp=0;
    cin>>n;
    string s;
    cin>>s;
    x=s.length();
    for(i=0;i<x;i++)
    {
        if(s[i]>=48&&s[i]<=57)
            digit++;
        else if(s[i]>=65&&s[i]<=90)
            large++;
        else if(s[i]>=97&&s[i]<=122)
            small++;
        else
            sp++;
    }
    if(digit==0)
        ans++;
    if(small==0)
        ans++;
    if(large==0)
        ans++;
    if(sp==0)
        ans++;
    if(x+ans<6)
        cout<<6-x;
    else
        cout<<ans;
    return 0;
}