#include<bits/stdc++.h>
using namespace std;
 /*for +-infinity => INT_MAX, INT_MIN,UINT_MAX,LONG_MIN,
LONG_MAX,ULONG_MAX,LLONG_MAX,LLONG_MIN,ULLONG_MAX */
#define FAST_IO ios_base::sync_with_stdio(false); cin.tie(0)
#define MOD                    1000000007
#define bitcount               __builtin_popcount
#define gcd                      __gcd
#define forall(i,a,b)           for(int i=a;i<b;i++)
#define foreach(v, c)        for( __typeof__( (c).begin()) v = (c).begin();  v != (c).end(); ++v)
#define all(a)                    a.begin(), a.end()
#define in(a,b)                  ( (b).find(a) != (b).end())
#define pb                        push_back
#define fill(a,v)                  memset(a, v, sizeof a)
#define sz(a)                    ((int)(a.size()))
#define mp                        make_pair
#define checkbit(n,b)        ( (n >> b) & 1)
#define DREP(a)               sort(all(a)); a.erase(unique(all(a)),a.end())
#define minin(a)                *min_element (all(a))
#define maxin(a)               *max_element(all(a))
#define asort(c)                 sort(all(c))
#define dsort(c)                 sort(all(c), greater<int>())
typedef  long long             ll;
typedef  vector<int>          vi;
typedef  pair<int, int>        ii;
typedef  vector<ii>             vii;
typedef  set<int>                si;
typedef  map<string, int>  msi;


int main()
{
   FAST_IO;
   int n,i;
    string num = "0123456789";
string low = "abcdefghijklmnopqrstuvwxyz";
string upp= "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
string sp= "!@#$%^&*()-+";
    int a[10]={0};
    string s;
    cin>>n>>s;
    
    for(i=0;i<n;i++)
    {
       if(num.find(s[i])!=-1)
           a[1]=1;
        else if(low.find(s[i])!=-1)
            a[2]=1;
        else if(upp.find(s[i])!=-1)
            a[3]=1;
        else if(sp.find(s[i])!=-1)
            a[4]=1;
    }
  int ans,cnt=0;
   for(i=1;i<=4;i++)
   {
    if(a[i]==0)
        cnt++;
   }
    if(n<6)
    {
       ans=cnt;
        if(n+cnt<6)
            ans+=(6-(n+cnt));
    }
    else
        ans=cnt;
    cout<<ans;
   return 0;
}