// 想定解（stoi でエンコード、map<int, int> で管理）
#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, t = stoi(s);
	if (dp.find(t) != dp.end())
	{
		ret = (used[t] ? 0 : dp[t] + mp[t]), used[t] = 1;
		return ret;
	}

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

	return dp[t] = ret;
}

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

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

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

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