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


int main() {
     int n;cin>>n;
    string s;cin>>s;
    int c1=0,c2=0,c3=0,c4=0;
    for(int i=0;i<n;i++)
    {
        if(s[i]>=65 && s[i]<=90) c1=1;
        else if(s[i]>=97 && s[i]<=122) c2=1;
        else if(s[i]>=48 && s[i]<=57) c3=1;                
         else c4++;        
                
    }
    int c=0;
    if(c1==0)c++;
    if(c2==0)c++;
    if(c3==0)c++;
    if(c4==0)c++;
    if((c+n)<6)
      c+=6-(c+n);
    cout<<c;
    
    return 0;
}