#define _USE_MATH_DEFINES
#include <math.h>
#include <memory.h>
#include <time.h>
#include <limits.h>
#include <vector>
#include <list>
#include <map>
#include <unordered_map>
#include <queue>
#include <deque>
#include <set>
#include <string>
#include <sstream>
#include <iostream>
#include <fstream>
#include <algorithm>
#include <iomanip>

using namespace std;
typedef long long     ll;
typedef unsigned int  UInt;
#define ALL(a)             (a).begin(), (a).end()
#define FOR(i,a,b)           for(int i = a,   end = (int)(b) ; i < end; ++i)
#define FOR_REV(i,a,b)       for(int i = b-1, rend = (int)(a); i >= rend; --i)
#define FOR_EACH(it,a)       for(remove_reference<decltype(a)>::type::iterator it = (a).begin(); it != (a).end(); ++it)
#define FOR_EACH_CONST(it,a) for(remove_reference<decltype(a)>::type::const_iterator it = (a).begin(); it != (a).end(); ++it)
#define FOR_EACH_REV(it,a)   for(remove_reference<decltype(a)>::type::reverse_iterator it = (a).rbegin(); it != (a).rend(); ++it)
#define IN_INT(a)       int a;      is >> a;
#define IN_INT2(a,b)    int a,b;    is >> a >> b;
#define IN_INT3(a,b,c)  int a,b,c;  is >> a >> b >> c;
template<class T> inline T   sqr(T v) { return v * v; }
template<class T> inline int sign(T v) {return v == 0 ? 0 : (v > 0 ? 1 : -1);}
template<class T> int get_bit(T v, int bit_index) { return (v >> bit_index) & 1; } //return {0,1}


istream& input()
{
  ios_base::sync_with_stdio(false);
  //#undef INPUT_FROM_FILE
#ifdef INPUT_FROM_FILE
  static ifstream is("HackerRank/input.txt");
#else
  istream& is = cin;
#endif
  return is;
}

ostream& output()
{
  cout << setprecision(15);
  return cout;
}

///////////////////////////////////////////4///////////////////////////////
//////////////////////////////////////////////////////////////////////////

//b
int main()
{
  istream& is = input();
  ostream& os = output();

  IN_INT(n);
  string s;
  is>>s;

  string chars[4] = {"0123456789","abcdefghijklmnopqrstuvwxyz","ABCDEFGHIJKLMNOPQRSTUVWXYZ","!@#$%^&*()-+"};
  vector<int> need(4,1);

  FOR (i,0,s.size())
  {
    FOR (j,0,4)
      if (need[j])
        FOR_EACH (it,chars[j])
          if (*it==s[i])
            need[j]=0;
  }

  int add=0;
  FOR (j,0,4)
    if (need[j])
      ++add;
  int res=max(6-n,add);

  os << res;
  return 0;
}



//////////////////////////////////////////////////////////////////////////

//int main()
//{
//  istream& is = input();
//  ostream& os = output();
//
//  int t;
//  for (is >> t; t; --t)
//  {
//    int n;
//    is >> n;
//    vector<int> a(n);
//    FOR (i,0,n)
//      is >> a[i];
//
//    //int res = 0;
//    //os << res;
//    os << "\n";
//  }
//  return 0;
//}