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


int main() {
    int n;
    cin>>n;
    string s;
    cin>>s;
    int i;  int d=0,u=0,l=0,s1=0;
    for(i=0;i<=n-1;i++) 
    {   if(isdigit(s[i])) d=1;
       else if(isupper(s[i])) u=1;
       else  if(islower(s[i])) l=1;
        else s1=1;
     }
  
    int p=4-d-u-l-s1;
    if(n>=6) cout<<p;
    else if(n+p>=6) cout<<p;
    else cout<<6-n;
    
    return 0;
}