#include <cassert>
#include<iostream>
#include<algorithm>
#include<cstdio>
#include<complex>
#include<vector>
#include<set>
#include<map>
#include<cmath>
#include<queue>
#include<string>
#include<cstdlib>
#include<memory.h>
#include<ctime>
#include<bitset>
#include<fstream>
#include<queue>
#include<stack>
#include<unordered_map>
#include<unordered_set>
#include<functional>

#define GT(it,v) for(auto it:v)
#define FU(i,a,b) for(int i=(a);i<(b);i++)
#define FD(i,a,b) for(int i=(a);i>(b);i--)
#define LL long long
#define LD long double
#define PI 3.1415926535897932384626
#define PII pair<int,int>
#define PLL pair<LL,LL>
#define VLL vector<long long > 
#define VVLL vector<vector<long long > >
#define VP vector<pair<long long, long long>>
#define MP make_pair
#define PB push_back 
#define FI first
#define SE second
#define SORT(v) sort(v.begin(),v.end())
#define GSORT(v,what) sort(v.begin(),v.end(),greater<what>())
using namespace std;

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	string nums = "0123456789", lets = "abcdefghijklmnopqrstuvwxyz", blets = "ABCDEFGHIJKLMNOPQRSTUVWXYZ", spec = "!@#$%^&*()-+",inp;
    cin>>inp;
	cin >> inp;
	int matches = 0;
	FU(i, 0, nums.size()) {
		FU(j, 0, inp.size()) {
			if (nums.at(i) == inp.at(j)) {
				matches++;
                 i=nums.size();
				break;
			}
		}
	}
	FU(i, 0, lets.size()) {
		FU(j, 0, inp.size()) {
			if (lets.at(i) == inp.at(j)) {
				matches++;
                 i=lets.size();
				break;
			}
		}
	}
	FU(i, 0, blets.size()) {
		FU(j, 0, inp.size()) {
			if (blets.at(i) == inp.at(j)) {
				matches++;
                 i=blets.size();
				break;
			}
		}
	}
	FU(i, 0, spec.size()) {
		FU(j, 0, inp.size()) {
			if (spec.at(i) == inp.at(j)) {
				matches++;
                 i=spec.size();
				break;
			}
		}
	}
	cout << max(6 - (int)inp.size(), 4 - matches);

	
	return 0;
}