bacT4 sIII 2

#include <iostream>
using namespace std;
int a[22][22], n, m;

void read() {
    cin >> m >> n;
    for (int i = 1; i <= m; i++) {
        for (int j = 1; j <= n; j++) {
            cin >> a[i][j];
        }
    }
}

bool arecompl(int col1, int col2) {
    for (int line = 1; line <= m; line++) {
        if (a[line][col1] == a[line][col2]) {
            return false;
        }
    }//*/
    return true;//*/
}

int main() {
    read();
    int ans = 0;
    for (int col = 2; col <= n; col++) {
        if (arecompl(1, col)) {
            ans++;
        }
    }
    cout << ans << endl;
    return 0;
}