#include <bits/stdc++.h>
#define int long long
using namespace std;
ifstream fin("tribute.in");
ofstream fout("tribute.out");
int v1[50001];
int v2[50001];
int solve_line(int l,int v[],int n)
{
    vector<int> st(50001,0);
    vector<int> dr(50001,0);
    vector<int> freq(50001,0);
    for(int i=0;i<n;i++)
    {
        freq[v[i]]++;
    }
    int cnt=freq[0];
    for(int i=1;i<50001;i++)
    {
        st[i]=st[i-1]+cnt;
        cnt+=freq[i];
    }
    cnt=freq[50000];
    for(int i=49999;i>=0;i--)
    {
        dr[i]=dr[i+1]+cnt;
        cnt+=freq[i];
    }
    int ans=LLONG_MAX;
    for(int i=0;i+l<=50000;i++)
    {
        ans=min(ans,st[i]+dr[i+l]);
    }
    return ans;
}
signed main()
{
    int n,dx,dy,x,y;
    fin>>n>>dx>>dy;
    for(int i=0;i<n;i++)
    {
        fin>>v1[i]>>v2[i];
    }
    fout<<solve_line(dx,v1,n)+solve_line(dy,v2,n);
    return 0;
}