#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
#define pii pair<int, int>
#define all(a) a.begin(), a.end()
#define sz(a) ((int)a.size())
const int mod = 998244353, N = 5005;

int n,x,y,l1[N],r1[N],l2[N],r2[N];
vector<int> ins_vec[N],del_vec[N];

int bit[N];
void add(int p, int x){
    //cout << "add " << p << ' ' << x << endl;
    for(++p; p<N; p+=p&-p) bit[p]+=x;
}
int query(int r){
    int res=0;
    for(++r; r; r-=r&-r) res+=bit[r];
    return res;
}
int find_next(int p){ // >= p
    int tar=query(p-1);
    //cout << "find_next " << p << ' ' << tar << endl;
    int cur=0,curval=0;
    for(int i=12; i>=0; --i) if(cur+(1<<i)<N&&curval+bit[cur+(1<<i)]<=tar){
        cur+=1<<i;
        curval+=bit[cur];
    }
    return cur;
}

int dp[N][N];
bool good[N];

int main() {
    ios::sync_with_stdio(false), cin.tie(0);
    cin >> n >> x >> y;
    for(int i=0; i<n; ++i){
        cin >> l1[i] >> r1[i] >> l2[i] >> r2[i];
        l1[i]-=x,r1[i]-=x,l2[i]-=y,r2[i]-=y;
        l1[i]=max(l1[i],0),l2[i]=max(l2[i],0);
        r1[i]=min(r1[i],n-1),r2[i]=min(r2[i],n-1);
    }
    for(int i=0; i<n; ++i){
        //cout << i << ' ' << l2[i] << ' ' << r2[i] << endl;
        ins_vec[l2[i]].pb(i),del_vec[r2[i]+1].pb(i);
    }
    memset(dp,0x3f,sizeof dp);
    dp[0][0]=0;
    for(int i=0; i<n; ++i){
        for(int j=0; j<n; ++j) good[j]=(l1[j]<=i&&i<=r1[j]);
        for(int j=0; i+j<n; ++j){
            for(int t: ins_vec[j]) if(good[t]) add(t,1);
            for(int t: del_vec[j]) if(good[t]) add(t,-1);
            if(dp[i][j]>=n) continue;
            int x=find_next(dp[i][j])+1;
            //cout << i << ' ' << j << ' ' << dp[i][j] << ' ' << x << endl;
            if(x<=n){
                dp[i+1][j]=min(dp[i+1][j],x);
                dp[i][j+1]=min(dp[i][j+1],x);
            }
        }
    }
    int res=0;
    for(int i=0; i<=n; ++i) for(int j=0; i+j<=n; ++j) if(dp[i][j]<=n) res=max(res,i+j);
    cout << res << "\n";
}