#include <fstream>
using namespace std;

const int MAX_N = 50022;

int N, DX, DY, sol;
int cnt_x[MAX_N], cnt_y[MAX_N], lx[MAX_N], rx[MAX_N], uy[MAX_N], dy[MAX_N], temp[MAX_N];

int main() {
    ifstream f("tribute.in");
    ofstream g("tribute.out");

    f >> N >> DX >> DY;
    for(int i = 1, x, y; i <= N; ++i) {
        f >> x >> y;
        ++cnt_x[x], ++cnt_y[y];
    }

    for(int i = 0; i < MAX_N; ++i)
        temp[i] = cnt_x[i];
    for(int i = 1; i + DX < MAX_N; ++i) {
        lx[i] = lx[i - 1] + cnt_x[i - 1];
        cnt_x[i] += cnt_x[i - 1];
    }
    for(int i = 0; i < MAX_N; ++i)
        cnt_x[i] = temp[i];
    for(int i = 50000; i >= 0; --i) {
        rx[i] = rx[i + 1] + cnt_x[i + 1];
        cnt_x[i] += cnt_x[i + 1];
    }

    for(int i = 0; i < MAX_N; ++i)
        temp[i] = cnt_y[i];
    for(int i = 1; i + DY < MAX_N; ++i) {
        uy[i] = uy[i - 1] + cnt_y[i - 1];
        cnt_y[i] += cnt_y[i - 1];
    }
    for(int i = 0; i < MAX_N; ++i)
        cnt_y[i] = temp[i];
    for(int i = 50000; i >= 0; --i) {
        dy[i] = dy[i + 1] + cnt_y[i + 1];
        cnt_y[i] += cnt_y[i + 1];
    }

    int best_x = lx[0] + rx[DX], best_y = uy[0] + dy[DY];
    for(int i = 1; i + DX < MAX_N; ++i)
        if(lx[i] + rx[i + DX] < best_x)
            best_x = lx[i] + rx[i + DX];
    for(int i = 1; i + DY < MAX_N; ++i)
        if(uy[i] + dy[i + DY] < best_y)
            best_y = uy[i] + dy[i + DY];
    sol = best_x + best_y;

    g << sol << "\n";


    f.close();
    g.close();

    return 0;
}