#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string s) {
    // Return the minimum number of characters to make the password strong
    string s2="!@#$%^&*()-+";int i,f1=1,f2=1,f3=1,f4=1,j;
    for(i=0;i<n;i++)
    {
        if(s[i]>='A' && s[i]<='Z')
        {
            f1=0;
        }
        
        if(s[i]>='a' && s[i]<='z')
        {
            f2=0;
        }
        
        if(s[i]>='0' && s[i]<='9')
        {
            f3=0;
        }
        for(j=0;j<s2.length();j++)
           {
               if(s[i]==s2[j])f4=0;
           }
    }
   // cout<<f1<<" "<<f2<<" "<<f3<<" "<<f4<<"\n";
    if(f1==0 && f2==0 && f3==0 && f4==0 && n>=6)return 0;
    else if(n>=6)return f1+f2+f3+f4;
    else 
    { int c=f1+f2+f3+f4;
     if(c+n>=6)return c;
     else return c+abs((c+n)-6);
            
    }
}

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