/***************************************************
 * Problem name : A.cpp
 * Problem Link :
 * OJ           :
 * Verdict      : Trying
 * Date         : 2017-11-02
 * Problem Type :
 * Author Name  : Saikat Sharma
 * University   : CSE,MBSTU
 ***************************************************/
#include<iostream>
#include<cstdio>
#include<algorithm>
#include<climits>
#include<cstring>
#include<string>
#include<sstream>
#include<cmath>
#include<vector>
#include<queue>
#include<cstdlib>
#include<deque>
#include<stack>
#include<map>
#include<set>
#define __FastIO ios_base::sync_with_stdio(false); cin.tie(0)
#define SET(a) memset(a,-1,sizeof(a))
#define pii pair<int,int>
#define pll pair <int, int>
#define debug printf("#########\n")
#define nl printf("\n")
#define sl(n) scanf("%lld", &n)
#define sf(n) scanf("%lf", &n)
#define si(n) scanf("%d", &n)
#define ss(n) scanf("%s", n)
#define pb push_back
#define MAX 100000
using namespace std;
typedef long long ll;
typedef unsigned long long ull;

template <typename T>
std::string NumberToString ( T Number ) {
    std::ostringstream ss;
    ss << Number;
    return ss.str();
}
ll gcd(ll a, ll b) {
    if (a % b == 0) return b;
    return gcd(b, a % b);
}
ll lcm(ll a, ll b) {
    return a * b / gcd(a, b);
}
/************************************ Code Start Here ******************************************************/
map<char, int>mp, mpa, mpA, mpn;
void pre() {
    for (int i = 0; i <= 9; i++) {
        char ch  = i + '0';
        mpn[ch] = 1;
    }
    for (char i = 'a'; i <= 'z'; i++) {
        mpa[i] = 1;
    }
    for (char i = 'A'; i <= 'Z'; i++) {
        mpA[i] = 1;
    }
    mp['!'] = 1, mp['@'] = 1, mp['#'] = 1, mp['$'] = 1;
    mp['%'] = 1, mp['^'] = 1, mp['&'] = 1, mp['*'] = 1;
    mp['('] = 1, mp[')'] = 1, mp['-'] = 1, mp['+'] = 1;
}
int main () {
    pre();
    int n, A, a, S, N;
    string str;
    scanf("%d", &n);
    getchar();
    cin >> str;
    A = a = S = N = 0;
    for (int i = 0; i < n; i++) {
        char ch = str[i];
        if (mp[ch] == 1) S = 1;
        else if (mpa[ch] == 1) a = 1;
        else if (mpA[ch] == 1) A = 1;
        else if (mpn[ch] == 1) N = 1;
    }
    int sum = S + a + A + N;
    if(n >= 6 && sum == 4){
        printf("0\n");
    }
    else {
        int x = 4 - sum;
        n = n + x;
        if(n>=6) printf("%d\n", x);
        else{
            n = 6 - n;
            printf("%d\n", n+x);
        }
    }
    return 0;
}