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

using ll = long long;
const ll MOD = 998'244'353;
//const ll MOD = 1000'000'007;

const ll INF = (1LL<<30)-1;
const ll LINF = (1LL<<62)-1;

//#define _GLIBCXX_DEQUE_BUF_SIZE 512

// int:[-2'147'483'648 : 2'147'483'647]
// ll:[-9'223'372'036'854'775'808 : 9'223'372'036'854'775'807]

#define rep(i, n) for (ll i = 0; i < (ll)(n); i++)
#define repi(i, a, n) for (ll i = a; i < (ll)(n); i++)
#define pb(a) push_back(a)
#define PS(a) cout<<(a)<<" ";
#define PL(a) cout<<(a)<<endl;
#define endl "\n"
//#define ONLINE_JUDGE 1
#ifdef ONLINE_JUDGE
    #define ES(a) while(0){}
    #define EL(a) while(0){}
#else
    #define NAME(a) #a
    #define ES(a) cerr<<NAME(a)<<": "<<(a)<<" ";
    #define EL(a) cerr<<NAME(a)<<": "<<(a)<<endl;
#endif
#define END(a) {PL(a) return;}
#define RES(a) cerr<<"\r"<<NAME(a)<<": "<<(a)<<"   ";
#define fi first
#define se second
#define ALL(a)  (a).begin(),(a).end()
#define RALL(a)  (a).rbegin(),(a).rend()
#define SORT(a) sort(a.begin(), a.end());
#define REVERSE(a) reverse(a.begin(), a.end());
#define ERASE(a) a.erase(unique(a.begin(), a.end()), a.end());
using Pii = pair<int, int>;
using Pll = pair<ll,ll>;
template <class T> using V = vector<T>;
template<typename T >ostream &operator<<(ostream &os, const vector< T > &v) {for(int i = 0; i < (int) v.size(); i++) {os << v[i] << (i + 1 != (int) v.size() ? " " : "");}return os;}
template<typename T >istream &operator>>(istream &is, vector< T > &v) {for(T &in : v) is >> in;return is;}
template<typename T, typename U > ostream &operator<<(ostream &os, const pair<T,U> &p) {os << p.first << ' ' << p.second; return os;}
template<typename T, typename U > istream &operator>>(istream &is, pair<T,U> &p) { is >> p.first >> p.second; return is;}
template<typename T, unsigned long int sz > ostream &operator<<(ostream &os, const array< T , sz > &v) {for(int i = 0; i < sz; i++) {os << v[i] << (i + 1 != (int) v.size() ? " " : "");}return os;}
template<typename T, unsigned long int sz > istream &operator>>(istream &is, array< T , sz > &v) {for(T& in:v){cin>>in;} return is;}
template<class T, class U > void chmin(T& t, const U& u) {if (t > u) t = u;}
template<class T, class U > void chmax(T& t, const U& u) {if (t < u) t = u;}



void solve() {

    ll N,K; cin>>N>>K;
    V<string> S(N); cin>>S;
    rep(i,N) S[i] += string(8-K,'0');
    sort(RALL(S));
    K = 8;

    V<ll> pos(K);
    //8
    int dp[5][5][5][5][5][5][5][5];

    auto dfs = [&](auto dfs, int d)->void {
        if(d==K){
            dp[pos[0]][pos[1]][pos[2]][pos[3]][pos[4]][pos[5]][pos[6]][pos[7]] = 0;
            return;
        }
        rep(i,5){
            pos[d] = i;
            dfs(dfs, d+1);
        }
    };
    dfs(dfs,0);



    rep(i,N){
        rep(j,K) pos[j] = S[i][j]-'0';
        if(dp[pos[0]][pos[1]][pos[2]][pos[3]][pos[4]][pos[5]][pos[6]][pos[7]]==-1) continue;

        auto dfs2 = [&](auto dfs2, int d)->void {
            if(d==K){
                dp[pos[0]][pos[1]][pos[2]][pos[3]][pos[4]][pos[5]][pos[6]][pos[7]] = -1;
                return;
            }
            for(ll k=S[i][d]-'0';k>=0;k--){
                pos[d] = k;
                dfs2(dfs2, d+1);
            }
        };
        dfs2(dfs2,0);

        rep(j,K) pos[j] = S[i][j]-'0';
        dp[pos[0]][pos[1]][pos[2]][pos[3]][pos[4]][pos[5]][pos[6]][pos[7]]=1;
    }


    ll ans = 0;
    auto dfs3 = [&](auto dfs3, int d)->void {
        if(d==K){
            if(dp[pos[0]][pos[1]][pos[2]][pos[3]][pos[4]][pos[5]][pos[6]][pos[7]]==1) ans++;
            return;
        }
        rep(i,5){
            pos[d] = i;
            dfs3(dfs3, d+1);
        }
    };
    dfs3(dfs3,0);

    PL(N-ans)

    return;
}

int main() {
   std::cin.tie(nullptr);
   std::ios_base::sync_with_stdio(false);
   std::cout << std::fixed << std::setprecision(15);
   int TT = 1;
   //cin>>TT;
   for(int tt = 0; tt<TT; tt++) solve();
   return 0;
}