#include <bits/stdc++.h>

using namespace std;

int n, m, k, i, j, nr;
string s;

int main() {
    // freopen ("a.in","r",stdin);
    cin >> n >> s;

    for (i = 0; i < n; i++)
        if (s[i] >= 'a' && s[i] <= 'z') {
            nr++;
            break;
        }

    for (i = 0; i < n; i++)
        if (s[i] >= 'A' && s[i] <= 'Z') {
            nr++;
            break;
        }

    for (i = 0; i < n; i++)
        if (s[i] >= '0' && s[i] <= '9') {
            nr++;
            break;
        }

    for (i = 0; i < n; i++)
        if (strchr("!@#$%^&*()-+", s[i])) {
            nr++;
            break;
        }


    if (n + 4 - nr >= 6) cout << 4 - nr;
    else cout << 6 - n;
    return 0;
}