#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string s) 
{
    int cap=0,sm=0,dig=0,sp=0;
    int x=4;
    
    
    for(int i=0;i<n;i++)
    {
    if( isdigit(s[i]) ) 
        dig=1;
    else if( isalpha(s[i]) )
    {
        if(s[i] >= 'A' && s[i] <= 'Z')
        {cap=1;}
        else if(s[i] >= 'a' && s[i] <= 'z')
        {sm=1;}
    }
    //if( s[i]=='!' || s[i]=='@' || s[i]=='#' || s[i]=='$' || s[i]=='%' || s[i]=='^' || s[i]=='&' || s[i]=='*'()-+") 
    else if( s[i]== '!' || '@' || '#' || '$' || '%' || '^' || '&' || '*' || '(' || ')' || '-' || '+' )
    {sp=1;}
    }
    if(cap==1)
    { x--;}
    if(sm==1)
    {x--;}
    if(dig==1)
    {x--;}
    if(sp==1)
    {x--;}
    
    if(n>=6)
        return x;
    else
    {
        if((6-n)>x)
            return (6-n);
        else
            return x;
        
    }
        // Return the minimum number of characters to make the password strong
}

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