#include <bits/stdc++.h>
using namespace std;
using Int = long long;
constexpr static int mod = 1e9 + 7;
constexpr static int inf = (1 << 30) - 1;
constexpr static Int infll = (1LL << 61) - 1;
int Competitive_Programming = (ios_base::sync_with_stdio(false), cin.tie(nullptr), cout << fixed << setprecision(15), 0);

#pragma region Debug Template

template <typename A, typename B>
string to_string(pair<A, B> p);

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);

string to_string(const string &s)
{
	return '"' + s + '"';
}

string to_string(const char *s)
{
	return to_string((string)s);
}

string to_string(bool b)
{
	return (b ? "true" : "false");
}

string to_string(vector<bool> v)
{
	bool first = true;
	string res = "{";
	for (int i = 0; i < static_cast<int>(v.size()); i++)
	{
		if (!first)
		{
			res += ", ";
		}
		first = false;
		res += to_string(v[i]);
	}
	res += "}";
	return res;
}

template <size_t N>
string to_string(bitset<N> v)
{
	string res = "";
	for (size_t i = 0; i < N; i++)
	{
		res += static_cast<char>('0' + v[i]);
	}
	return res;
}

template <typename A>
string to_string(A v)
{
	bool first = true;
	string res = "{";
	for (const auto &x : v)
	{
		if (!first)
		{
			res += ", ";
		}
		first = false;
		res += to_string(x);
	}
	res += "}";
	return res;
}

template <typename A, typename B>
string to_string(pair<A, B> p)
{
	return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p)
{
	return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ")";
}

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p)
{
	return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T)
{
	cerr << " " << to_string(H);
	debug_out(T...);
}

#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif
#pragma endregion

int enc(string s)
{
	int ret = 0;
	for (int i = 0; i < s.size(); i++)
	{
		ret *= 4;
		ret += s[i] - 'A';
	}
	return ret;
}

int dfs(string &s, vector<int> &dp, vector<int> &mp, vector<int> &used)
{
	int e = enc(s);
	if (dp[e] != -1)
	{
		int ret = (used[e] ? 0 : dp[e] + mp[e]);
		// dp[e] = 0;
		used[e] = 1;
		return ret;
	}
	// used[e] = 1;

	int ret = 0, K = s.size();

	for (int i = 0; i < K; i++)
	{
		if (s[i] == 'D')
			continue;
		s[i]++;
		ret += dfs(s, dp, mp, used);
		if(used[enc(s)] == 0 and mp[enc(s)] == 1)
			ret++;
		used[enc(s)] = 1;
		s[i]--;
	}

	dp[e] = ret;

	// debug_out(s, dp[e], e);

	return ret;
}

int main()
{
	int N, K;
	cin >> N >> K;
	vector<string> s(N);
	vector<int> mp(1 << (2 * K));

	for (int i = 0; i < N; i++)
	{
		cin >> s[i];
		mp[enc(s[i])]++;
		// debug_out(s[i], enc(s[i]));
	}

	vector<int> used(1 << (2 * K)), dp(1 << (2 * K), -1);

	int ans = 0;

	for (int i = 0; i < N; i++)
	{
		int t = dfs(s[i], dp, mp, used);
		ans += t;
		// debug_out(s[i], t);
		dp[enc(s[i])] = 0;
	}

	cout << ans << endl;

	// debug_out(mp, dp);
}