#include<algorithm>

#include<iostream>

#include<cstdlib>

#include<cstring>

#include<cstdio>

#include<cmath>

using namespace std;

typedef long long LL;

#define N 10010

struct data

{

    LL h,s,sum;

}x[N],y[N];

LL n,A,B,C;

LL minn,maxn;

LL ans,cnt,l,r;

LL getLL()

{

    LL x=0,f=1;char ch=getchar();

    while(ch>'9'||ch<'0'){if(ch=='-')f=-1;ch=getchar();}

    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}

    return x*f;

}

LL cmp1(const data &a,const data &b)

{

    return a.h<b.h;

}

LL cmp2(const data &a,const data &b)

{

    return a.sum<b.sum;

}

bool check1(LL p)

{

    return y[p].s<=maxn && y[p].s>=minn;

}

bool check2(LL p)

{

    return x[p].s<=maxn && x[p].s>=minn;

}

int main()

{

    n=getLL(),A=getLL(),B=getLL(),C=getLL();

    for (LL i=1;i<=n;i++)

    {

        x[i].h=getLL();

        x[i].s=getLL();

        x[i].sum=A*x[i].h+B*x[i].s;

        y[i]=x[i];

    }

    sort(x+1,x+n+1,cmp1);

    sort(y+1,y+n+1,cmp2);

    for (LL i=1;i<=n;i++)

    {

        minn=x[i].s;

        maxn=minn+C/B;

        l=r=cnt=0;

        for (LL j=1;j<=n;j++)

        {

            while (r<n && y[r+1].sum<=A*x[j].h+B*x[i].s+C)

                r++,cnt+=check1(r);

            while (l<n && x[l+1].h<x[j].h)

                l++,cnt-=check2(l);

            ans=max(ans,cnt);

        }

    }

    printf("%lld\n",ans);

    return 0;

}