#include <bits/stdc++.h>

using namespace std;

long long solve(vector<int> &X, int DX) {
    int max_coord = *max_element(X.begin(), X.end());
    vector<long long> cost_le(max_coord + 1), cost_ri(max_coord + 1);
    vector<int> freq(max_coord + 1);
    if(DX > max_coord) {
        return 0;
    }
    for(auto x : X) {
        freq[x]++;
    }
    
    int cnt = freq[0];
    for(int i = 1; i <= max_coord; i++) {
        cost_le[i] = cost_le[i - 1] + cnt;
        cnt += freq[i];
    }

    cnt = freq[max_coord];
    for(int i = max_coord - 1; i >= 0; i--) {
        cost_ri[i] = cost_ri[i + 1] + cnt;
        cnt += freq[i];
    }

    long long ret = LLONG_MAX;
    for(int i = 0; i <= max_coord - DX; i++) { ///daca DX > max_coord
        ret = min(ret, cost_le[i] + cost_ri[i + DX]);
    }
    return ret;
}

int main() {
#ifndef LOCAL
    freopen("tribute.in", "r", stdin);
    freopen("tribute.out", "w", stdout);
#endif
    ios::sync_with_stdio(false);
    cin.tie(0);

    int N, DX, DY;
    cin >> N >> DX >> DY;
    vector<int> X(N), Y(N);
    for(int i = 0; i < N; i++) {
        cin >> X[i] >> Y[i];
    }

    cout << solve(X, DX) + solve(Y, DY) << "\n";
    return 0;
}