#include <fstream>
using namespace std;

ifstream fin("tribute.in");
ofstream fout("tribute.out");

int n, dx, dy;
int cntx[50001], cnty[50001];

long long Solve(int d, int *cnt)
{
    long long l=0, r=0;
    long long s=0, ans=6e9;
    for (int i=50000; i>=d; --i)
    {
        r+=cnt[i];
        s+=r;
    }
    for(int i=0; i<50001-d; ++i)
    {
        s-=r;
        r-=cnt[i+d];
        ans=min(ans, s);
        l+=cnt[i];
        s+=l;
    }
    return ans;
}

int main()
{
    fin>>n>>dx>>dy;
    for(int i=0;i<n;++i)
    {
        int x, y;
        fin>>x>>y;
        ++cntx[x];
        ++cnty[y];
    }
    fout<<Solve(dx, cntx)+Solve(dy, cnty)<<"\n";
    return 0;
}