// 2024 IUSB Programming Competition
// Round 1 Problem 3
// Grid Count
// Solution by Liguo Yu

#include <iostream>
using namespace std;

int main()
{
    int m, n;
    cin >> m >> n;
    int **array = new int*[m];
    
    for (int i = 0; i < m; i++)
    {
        array[i] = new int[n];
        for (int j = 0; j < n; j++)
        {
            cin >> array[i][j];
        }
    }
    
    bool *result = new bool[n];
    
    for (int j = 0; j < n; j++)
    {
        result[j] = true;
    }
    
    for (int i = 1; i < m; i++)
    {
        for (int j = 0; j < n; j++)
        {
            if (array[i][j] < array[i - 1][j])
                result[j] = false;
        }
    }
    
    int count = 0;
    
    for (int j = 0; j < n; j++)
    {
        if (result[j] == true)
            count++;
    }

    cout << count << endl;

    return 0;
}