#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#include <unordered_map>
#include <unordered_set>

using namespace std;

#define scan(n) scanf("%d",&n)
#define print(n) printf("%d",n)
#define all(c) c.begin(),c.end()
#define MAX 1e9+10
const int mod = 1000000007;
#define ll long long
#define pb push_back

#define trace1(x)       cerr << #x << " : " << x << endl;
#define trace2(x, y)    cerr << #x << " : " << x << " | " << #y << " : " << y << endl;
#define trace3(x, y, z) cerr << #x << " : " << x << " | " << #y << " : " << y << " | " << #z << " : " << z << endl;


int main()
{
	ios_base::sync_with_stdio(false); cin.tie(NULL);
	int test = 1;
//	cin >> test;
	while(test--) {
		int l;
		cin >> l;
		string s;
		cin >> s;

		string numbers = "0123456789";
		string lower_case = "abcdefghijklmnopqrstuvwxyz";
		string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
		string special_characters = "!@#$%^&*()-+";

		int count = 0;
		for(auto x: s) {
			if(numbers.find(x)  != std::string::npos) {
				count++;
				break;
			}
		}

		for(auto x: s) {
			if(lower_case.find(x)  != std::string::npos) {
				count++;
				break;
			}
		}
		
		for(auto x: s) {
			if(upper_case.find(x)  != std::string::npos) {
				count++;
				break;
			}
		}

		for(auto x: s) {
			if(special_characters.find(x) != std::string::npos) {
				count++;
				break;
			}
		}

		//cout << count << endl;
		int newl = l + 4 - count;
		if(newl >= 6)
			cout << 4 - count << endl;
		else
			cout << 6 - newl + 4 - count << endl;
	}
	return 0;
}