#include<bits/stdc++.h>
using namespace std;


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int n;
    cin>>n;
    string str;
    cin>>str;
    int uppercase=1,lowercase=1,special=1,digit=1;
    //!@#$%^&*()-+
    map<char,int>mp;
    mp['!']=1;
    mp['@']=1;
    mp['#']=1;
    mp['$']=1;
    mp['%']=1;
    mp['^']=1;
    mp['&']=1;
    mp['*']=1;
    mp['(']=1;
    mp[')']=1;
    mp['-']=1;
    mp['+']=1;
    for(int i=0;i<n;i++)
    {
        if(uppercase && str[i]>=65 && str[i]<=90)
            uppercase--;
        if(lowercase && str[i]>=97 && str[i]<=122)
            lowercase--;
        if(digit && str[i]>='0' && str[i]<='9')
            digit--;
        if(mp[str[i]]==1 && special)
            special--;
    }
    int ans = uppercase+lowercase+special+digit;
    if(n>=6)
    {
        printf("%d",ans);
    }
    else
    {
        printf("%d",max(ans,6-n));
    }
    return 0;
}