#include<bits/stdc++.h>
#define ll long long
using namespace std;
int n,x,y;
int g[2000][2000],m[2000][2000];
queue<pair<int,int>> f;
vector<pair<int,int>> s;
int ans,flag;
int c[5]={0,0,1,0,-1},d[5]={0,-1,0,1,0};
int check(int a,int b)
{
	if(a>=0&&b>=0&&a<=1005&&b<=1005) return 1;
	return 0;
}
int main(){
	freopen("tractor.in","r",stdin);
	freopen("tractor.out","w",stdout);
cin>>n>>x>>y;
for(int q=1;q<=n;q++)
{
	int a,b;
	cin>>a>>b;
	g[a][b]++;
}
f.push({x,y});
while(1)
{
	while(f.size())
	{
		int a,b;
		a=f.front().first,b=f.front().second;
		f.pop();
		for(int q=1;q<=4;q++)
		{
			if(check(a+c[q],b+d[q])&&m[a+c[q]][b+d[q]]==0)
			{
				m[a+c[q]][b+d[q]]=1;
				if(g[a+c[q]][b+d[q]]==0)
				{
					if(a+c[q]==0&&b+d[q]==0) flag=1;
					f.push({a+c[q],b+d[q]});
				}else
				{
					s.push_back({a+c[q],b+d[q]});
				}
			}
		}
		if(flag==1) break;
	}
	if(flag==1) break;
	ans++;
	for(pair<int,int> q:s)
	{
		g[q.first][q.second]=0;
		f.push({q.first,q.second});
	}
	s.clear();
}
cout<<ans;
return 0;
}