#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
string numbers = "0123456789";
string lower_case = "abcdefghijklmnopqrstuvwxyz";
string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
string special_characters = "!@#$%^&*()-+";

int isnumber(char c){
    string str=numbers;
    int n=str.size();
    for(int i=0;i<n;i++)
    {
        if(str[i]==c)
            return 1;
    }
    return 0;
}
int islower(char c){
    string str=lower_case;
    int n=str.size();
    for(int i=0;i<n;i++)
    {
        if(str[i]==c)
            return 1;
    }
    return 0;
}
int isupper(char c){
    string str=upper_case;
    int n=str.size();
    for(int i=0;i<n;i++)
    {
        if(str[i]==c)
            return 1;
    }
    return 0;
}
int isspecial(char c){
    string str=special_characters;
    int n=str.size();
    for(int i=0;i<n;i++)
    {
        if(str[i]==c)
            return 1;
    }
    return 0;
}
int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int n;
    cin>>n;
    string str;
    cin>>str;
    int num=0,l=0,u=0,s=0;
    for(int i=0;i<str.size();i++)
    {
        if(isnumber(str[i]))
            num=1;
        else if(islower(str[i]))
            l=1;
        else if(isupper(str[i]))
            u=1;
        else if(isspecial(str[i]))
            s=1;
        else
            continue;
    }
    int tot=num+l+u+s;
    if(num && l && u && s)
    {
     if(n>=6)
     {
         cout<<0<<endl;
     }
         else
     {
         cout<<(6-n)<<endl;
     }
    }
    else
    {
        if(n>=6)
        {
            cout<<(4-tot)<<endl;
        }
            else
            cout<<(4-tot)+max(0,(6-(4-tot+n)))<<endl;
    }
    return 0;
}