#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
    // Return the minimum number of characters to make the password strong
    int a[5]={0,0,0,0,0};
    int r=0;
    
    
    if(n>=6)
           a[0]=1;
      
        for(int i=0;i<n;i++)
        {
            if(password[i]>=65 && password[i]<=90)
                a[3]=1;
             if(password[i]>=97 && password[i]<=122)
                a[2]=1;
             if(password[i]>=48 && password[i]<=57)
                a[1]=1;
            
            if(password[i]=='!'||password[i]=='&'||password[i]=='@'||password[i]=='#'||password[i]=='('||password[i]==')'||password[i]=='$'||password[i]=='%'||password[i]=='+'||password[i]=='-'||password[i]=='*'||password[i]=='^')
                a[4]=1;
                
        }
    int count=0;
    for(int i=0;i<5;i++)
    { 
        if(a[i]==0)
            count++;
    }
    if(a[0]==1)
        r=count;
    else
    {
       if((n+count-1)>=6)
           r=count-1;
        else
            r= 6-n;
    }
        
    
    return r; 
}

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