#include <bits/stdc++.h>
using namespace std;
int ID(int a = 0, int b = 0, int c = 0, int d = 0, int e = 0, int f = 0, int g = 0, int h = 0) {
    return (a + 5 * (b + 5 * (c + 5 * (d + 5 * (e + 5 * (f + 5 * (g + 5 * h)))))));
}
int ID(array<int, 8> arr) {
    return ID(arr[0], arr[1], arr[2], arr[3], arr[4], arr[5], arr[6], arr[7]);
}
const int sss = 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5;
inline int nxx(int id, int a) {
    int x = 1;
    for (int i = 0; i < a; i ++) {
        x *= 5;
    }
    id += x;
    return id;
}
int main () {
    int N, K;
    cin >> N >> K;
    int num[sss];
    for (int& a : num) {
        a = 0;
    }
    int A[200020];
    for (int i = 0; i < N; i ++) {
        int id = 0;
        A[i] = 0;
        string s;
        int bb = 1;
        cin >> s;
        for (auto a : s) {
            a -= '0';
            id += a * bb;
            bb *= 5;
        }
        num[id] ++;
        A[i] = id;
    }
    for (int p = 0; p < 8; p ++) {
        for (int i = sss - 1; i >= 0; i --) {
            int nx = nxx(i, p);
            if (nx < sss) {
                num[i] += num[nx];
            }
        }
    }
    int ans = 0;
    for (auto& a : A) {
        ans += (num[a] > 1);
    }
    cout << ans << endl;
}