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#include <bits/stdc++.h>

using namespace std;

int calcMax(int & a, int & b, vector < int > & cow_x, vector < int > & cow_y, int & n, int & B) {

    int q1 = 0, q2 = 0, q3 = 0, q4 = 0;

    for (int i = 0; i < n; i++) {
        if (cow_x[i] > a && cow_y[i] > b) q1++;
        else if (cow_x[i] < a && cow_y[i] > b) q2++;
        else if (cow_x[i] < a && cow_y[i] < b) q3++;
        else q4++;
    }

    return max({
        q1,
        q2,
        q3,
        q4
    });

}

int main() {
    int n, B;
    cin >> n >> B;

    vector < int > cow_x(n);
    vector < int > cow_y(n);

    for (int i = 0; i < n; i++) {
        cin >> cow_x[i] >> cow_y[i];
    }

    int a_max = 0, b_max = 0, min_max = n + 1;


    for (int a = 0; a <= B; a += 2) {
        for (int b = 0; b <= B; b += 2) {
            int max_cows = calcMax(a, b, cow_x, cow_y, n, B);
            if (max_cows < min_max) {
                min_max = max_cows;
            }
        }
    }

    cout << min_max;
}