PIN

#define task "PIN"

#include <iostream>
#include <cstdio>

using namespace std;

using ll = long long;
using ld = long double;
;

constexpr int N = 2e5 + 5;
constexpr int Inf = 1e9 + 7;
int n, d;
int cnt[N * 10];
int Pow[5], f[N];

void Read()
{
    cin >> n >> d;
    d = 4 - d;
    Pow[0] = 1;
    Pow[1] = 37;
    Pow[2] = 1369;
    Pow[3] = 50653;
}

#define Get(x) ((x >= 'a' && x <= 'z') ? (x - 'a' + 1) : (x - '0' + 1) + 26)
#define bit(i, x) (((x) >> (i)) & 1)

int Val(const string &s, const int &i)
{

    int ans(0);
    for (int j = 0; j < 4; ++j)
        if (bit(j, i))
            ans += Get(s[j]) * Pow[j];
    return ans;
}

void Solve()
{
    ll ans(0);

    while (n--)
    {
        string s;
        cin >> s;

        for (int i = 15; ~i; --i)
        {
            f[i] = cnt[Val(s, i)];
            for (int j = i + 1; j < 16; ++j)
                if ((i & j) == i)
                    f[i] -= f[j];
            if (__builtin_popcount(i) == d)
                ans += f[i];
        }

        for (int i = 0; i < 16; ++i)
            ++cnt[Val(s, i)];
    }
    cout << ans;
}

int32_t main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    if (fopen(task ".INP", "r"))
    {
        freopen(task ".INP", "r", stdin);
        freopen(task ".OUT", "w", stdout);
    }
    Read();
    Solve();
}