// 想定解
#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);

int dfs(string &s, map<int, int> &dp, map<int, int> &mp, map<int, int> &used)
{
	int ret = 0;
	if (dp.find(stoi(s)) != dp.end())
	{
		ret = (used[stoi(s)] ? 0 : dp[stoi(s)] + mp[stoi(s)]), used[stoi(s)] = 1;
		return ret;
	}

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

	return dp[stoi(s)] = ret;
}

int main()
{
	int N, K;
	cin >> N >> K;
	vector<string> s(N);
	map<int, int> used, dp, mp;
	int ans = 0;

	for (int i = 0; i < N; i++)
	{
		cin >> s[i];
		mp[stoi(s[i])]++;
	}

	for (int i = 0; i < N; i++)
		ans += dfs(s[i], dp, mp, used), dp[stoi(s[i])] = 0;

	cout << ans << '\n';
}