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

string num = "0123456789";
string lc = "abcdefghijklmnopqrstuvwxyz";
string uc = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
string sc = "!@#$%^&*()-+";


int main() 
{
    int n;
    cin>>n;
    string s;
    cin>>s;
    int id=0,ilc=0,iuc=0,isc=0;
    for(int i=0;i<n;i++)
    {
        if(num.find(s[i])!=string::npos)
            id++;
        if(lc.find(s[i])!=string::npos)
            ilc++;
        if(uc.find(s[i])!=string::npos)
            iuc++;
        if(sc.find(s[i])!=string::npos)
            isc++;       
    }
    int cnt=0;
    if(id==0)
        cnt++;
    if(ilc==0)
        cnt++;
    if(iuc==0)
        cnt++;
    if(isc==0)
        cnt++;
    
    if((n+cnt)>=6)
        cout<<cnt;
    else
        cout<<6-n;
    
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    return 0;
}