#include<bits/stdc++.h>
#define N 3005
using namespace std;
int f[N][N];
int n,x,y;
int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    cin>>n>>x>>y;
    memset(f,-1,sizeof(f));
    f[1][0]=0;
    for(int i=1;i<=n;++i){
        int a,b,c,d;
        cin>>a>>b>>c>>d;
        for(int j=0;j<i;++j)
            if(f[i][j]!=-1){
                if(a<=x+j&&x+j<=b&&c<=y+f[i][j]&&y+f[i][j]<=d){
                    f[i+1][j+1]=max(f[i+1][j+1],f[i][j]);
                    f[i+1][j]=max(f[i+1][j],f[i][j]+1);
                }
            }
    }
    int ans=0;
    for(int i=0;i<=n;++i)
        if(f[n+1][i]!=-1)
            ans=max(ans,f[n+1][i]+i);
    cout<<ans<<'\n';
    return 0;
}