#include <bits/stdc++.h>

using namespace std;
int temp[]={0,0,0,0,0};
string sp="!@#$%^&*()-+";
int check(char ch)
{
    for(int i=0;i<sp.length();i++)
        if(ch==sp[i])
             return 1;
    return 0;
    
}
int minimumNumber(int n, string pass) {
 
    for(int i=0;i<n;i++)
    {
        if(isdigit(pass[i]))
            temp[1]=1;
        else if(isupper(pass[i]))
            temp[2]=1;
        else if(islower(pass[i]))
            temp[3]=1;
        else if(check(pass[i]))
            temp[4]=1;
        
        temp[0]+=1;  
    }    
    int c=0;
    for(int i=1;i<=4;i++)
    {     
        //cout<<temp[i]<<" ";
        if(temp[i]==0)
               c++,temp[0]+=1;
     
    }
    if(temp[0]<6)
        c+=6-temp[0];
    return c;
    
}

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