#include <fstream>
using namespace std;
ifstream in("tribute.in");
ofstream out("tribute.out");
int v1[50005],v2[50005];
int minn2=sy,minn=sx;;
int sx=0,sy=0;
int n=0,i,x,y,a,b,dx=0,dy=0,p,m;
int main()
{
    in>>n>>dx>>dy;
    for(i=1;i<=n;i++)
    {
        in>>x>>y;
        sx+=x;
        sy+=y;
        v1[x]++;
        v2[y]++;
    }
    for(a=-dx,b=0,p=0,m=n;a<=50000;a++,b++)
    {
        if(sx<minn)
            minn=sx;

        if(a>=0)
            p+=v1[a];
        if(b<50005)
            m-=v1[b];

        sx-=m;
        sx+=p;
    }
    b=0;
    p=0;
    m=n;
    for(a=-dy;a<=50000;a++)
    {
        if(sy<minn2)
            minn2=sy;
        if(a>=0)
            p+=v2[a];
        if(b<50005)
            m-=v2[b];

        sy-=m;
        sy+=p;
        b++;
    }
    out<<minn+minn2<<endl;
    return 0;
}