#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string s) {
    int p1=1,p2=1,p3=1,p4=1;
    for(int i=0;i<n;++i)
    {
        if(int(s[i])>=65&&int(s[i])<=90)
        {
            p1=0;
            break;
        }
        else 
            p1=1;
    }
    for(int i=0;i<n;++i)
    {
        if(int(s[i])>=97&&int(s[i])<=122)
        {
            p2=0;
            break;
        }
        else 
            p2=1;
    }
    for(int i=0;i<n;++i)
    {
        if(int(s[i])>=48&&int(s[i])<=57)
        {
            p3=0;
            break;
        }
        else 
            p3=1;
    }
    for(int i=0;i<n;++i)
    {
        if(s[i]=='!'||s[i]=='@'||s[i]=='#'||s[i]=='$'||s[i]=='%'||s[i]=='^'||s[i]=='&'||s[i]=='*'||s[i]=='('||s[i]==')'||s[i]=='-'||s[i]=='+')
        {
            p4=0;
            break;
        }
        else 
            p4=1;
    }
    return p1+p2+p3+p4;
}

int main() {
    int n;
    cin >> n;
    string password;
    cin >> password;
    int answer = minimumNumber(n, password);
    if(answer+n<6)
    cout << 6-n << endl;
    else
        cout<<answer<<endl;
    return 0;
}