#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) 
{
    int i=0,tc;
    int lc=0,uc=0,sc=0,num=0;
    for(i=0;i<n;i++)
    {
       tc=password[i];
          if((tc>=48)&&(tc<=57))
            num++;
          if((tc>=65)&&(tc<=90))
            uc++;
          if((tc>=97)&&(tc<=122))
            lc++;
          if((tc==33)||(tc==64)||(tc==35)||(tc==36)||(tc==37)||(tc==94)||(tc==38)||(tc==40)||(tc==41)||(tc==42)||(tc==43)||(tc==45))
            sc++;
    }
    int k=0;
    if(lc==0)
        k++;
    if(uc==0)
        k++;
    if(sc==0)
        k++;
    if(num==0)
        k++;
    if((n+k)>=6)
        return k;
    else 
        return (6-n);
}
    
    
    int main()
    {
        int n;
    cin >> n;
    string password;
    cin >> password;
    int answer = minimumNumber(n, password);
    cout << answer << endl;
    return 0;
    }