#include <iostream>
#include <numeric>
#include <algorithm>

using namespace std;

constexpr int Z = 40;

void dfs(int cnt[10], int n, int a, bool f[]) {
    if (n == 0) {
        f[a%Z] = true;
        return;
    }

    for (int i = 0; i < 10; i++) {
        if (cnt[i] > 0) {
            cnt[i]--;
            dfs(cnt, n - 1, a * 10 + i, f);
            cnt[i]++;
        }
    }
}

int main() {
    int n;
    cin >> n;
    int cnt[10] = {0};
    for (int i = 0; i < n; i++) {
        char c;
        cin >> c;
        cnt[c-'0']++;
    }

    for (int i = 0; i < n; i++) {
        cnt[i] = min(cnt[i], 3);
    }

    bool f[Z] = {false};
    dfs(cnt, min(3, n), 0, f);

    cout << accumulate(f, f + Z, 0) << endl;

    return 0;
}