#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int pow5[10];
  pow5[0] = 1;
  rep(i, 9) pow5[i + 1] = pow5[i] * 5;
  int n, k;
  cin >> n >> k;
  VI s(n);
  rep(i, n) {
    rep(_, k) {
      char c;
      cin >> c;
      s[i] = 5 * s[i] + (c - '0');
    }
  }
  VI d(pow5[k]);
  for(int x: s) d[x]++;
  rep(z, k) {
    rrep(s, pow5[k]) if (s / pow5[z] % 5) {
      d[s - pow5[z]] += d[s];
    }
  }
  int ans = 0;
  for(int x: s) ans += d[x] > 1;
  cout << ans << '\n';
}