#include <bits/stdc++.h>
using namespace std;
#define rep(i,l,r) for (int i = (l); i <= (r); i++)
#define per(i,r,l) for (int i = (r); i >= (l); i--)
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define SZ(x) ((int)(x).size())
#define maxn(a, b) a = max(a, b)
#define minn(a, b) a = min(a, b)
typedef vector<int> VI;
typedef long long ll;
typedef pair<int,int> PII;
typedef double db;
const ll mod = 998244353;
mt19937 gen(random_device{}());
ll rp(ll a,ll b) {ll res=1%mod;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;}

const int N = 5043;
int n, s, t;
int xl[N], xr[N], yl[N], yr[N];
int dp[N][N];
bitset<N> f[N], pre[N], suf[N];

int main() {
    scanf("%d%d%d", &n, &s, &t);
    rep(i,1,n) {
        scanf("%d%d%d%d", &xl[i], &xr[i], &yl[i], &yr[i]);
        xl[i] -= s, xr[i] -= s;
        yl[i] -= t, yr[i] -= t;
    }
    pre[0].set(0);
    rep(i,1,n) {
        pre[i]=pre[i-1];
        pre[i].set(i);
    }
    suf[n].set(n);
    per(i,n-1,0) {
        suf[i]=suf[i+1];
        suf[i].set(i);
    }
    f[0].set(0);
    rep(i,1,n) {
        per(j,i,0) {
            if (xl[i] <= j && j <= xr[i]) {
                bitset<N> tmp=f[j];
                int l = yl[i], r = yr[i];
                if (l) tmp = tmp | pre[l - 1];
                if (r < i) tmp = tmp | suf[r + 1];
                f[j] = f[j]|(tmp<<1);
                f[j+1] = f[j+1]|tmp;
            }
        }
    }
    int ans = 0;
    rep(i,0,n) rep(j,0,n) if (f[i][j]) {
        maxn(ans, n - (i + j));
    }
    printf("%d\n", ans);
    return 0;
}