#include <bits/stdc++.h>
using namespace std;

int n, res = 0;
string a[29];
int b[29], f[(1 << 26)];

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    cin >> n;
    for (int i = 0; i < n; i++)
    {
        cin >> a[i];
        int mask = 0;
        for (char c : a[i])
        {
            int cur = c - 'a';
            mask |= (1 << cur);
        }
        b[i] = mask;
    }

    for (int mask = 1; mask < (1 << n); mask++)
    {
        int bit = __builtin_ffs(mask) - 1;
        f[mask] = (b[bit] | f[mask - (1 << bit)]);
        if (f[mask] == (1 << 26) - 1) res++;
    }
    cout << res;

    return 0;
}