//#define _GRIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;

// ?????¬???????????¬??????
#pragma region MACRO
#define P(x) cout << (x) << endl
#define p(x) cout << (x)
#define PED cout << "\n"
#define rep(i,n) for(int i=0; i<(int)n; ++i)
#define REP(i,x,n) for(int i=x; i<(int)n; ++i)
#define repi(i,n) for(int i=0; i<=(int)n; ++i)
#define REPI(i,x,n) for(int i=x; i<=(int)n; ++i)
#define ILP while(true)
#define FOR(i,c) for(__typeof((c).begin())!=(c).begin(); i!=(c).end(); ++i)
#define ALL(c) (c).begin(), (c).end()
#define mp make_pair
#pragma endregion

// ???
#pragma region TYPE_DEF
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<string, string> pss;
typedef pair<string, int> psi;
typedef pair<int, string> pis;
typedef vector<int> vi;
typedef vector<double> vd;
typedef vector<long double> vld;
typedef vector<long> vl;
typedef vector<long long> vll;
typedef vector<string> vs;
#pragma endregion

// Effective std
#pragma region ESTD
template<typename C, typename T> int count(C& c, T t) { return count(ALL(c), t); }
template<typename C, typename F> int count_if(C& c, F f) { return count_if(ALL(c), f); }
template<typename C, typename T> void erase(C& c, T t) { remove(ALL(c), t), c.end(); }
template<typename C> void remove(vector<C>& c, unsigned int index) { c.erase(c.begin()+index); }
template<typename C, typename T, typename U> void replace(C& c, T t, U u) { replace(ALL(c), t, u); }
template<typename C, typename F, typename U> void replace_if(C& c, F f, U u) { (ALL(c), f, u); }
template<typename C> void reverse(C& c) { reverse(ALL(c)); }
template<typename C> void sort(C& c) { sort(ALL(c)); }
template<typename C, typename Pred> void sort(C& c, Pred p) { sort(ALL(c), p); }
#pragma endregion

// ?????°
#pragma region CONST_VAL
constexpr int PI = (2*acos(0.0));
constexpr int EPS = (1e-9);
constexpr int MOD = (int)(1e9+7);
constexpr int INF = 100000000;
#pragma endregion

#define int long long

const int MAX = 100;
char flag[MAX*2][MAX*2];

signed main()
{
    while(true) {
        int t, n;
        cin >> t >> n;
        if(t==0&&n==0) break;
        fill(flag[0], flag[MAX*2-1]+MAX*2, 0);
        for(int i=0; i<n; ++i) {
            int x, y;
            cin >> x >> y;
            flag[y+MAX][x+MAX] = 1;
        }
        int sx, sy;
        cin >> sx >> sy;

        queue<pair<pair<int,int>, int> > q;
        q.push(make_pair(pair<int, int>(sx,sy),0));
        int c = 0;
        while(!q.empty()) {
            pair<pair<int, int>, int> p = q.front();
            pair<int, int> a = p.first;
            int step = p.second;
            q.pop();

            if(flag[a.second+MAX][a.first+MAX]) continue;
            flag[a.second+MAX][a.first+MAX] = 1;
            c++;
            if(step<t) {
                q.push(make_pair(pair<int,int>(a.first+1,a.second),step+1));
                q.push(make_pair(pair<int,int>(a.first-1,a.second),step+1));
                q.push(make_pair(pair<int,int>(a.first,a.second+1),step+1));
                q.push(make_pair(pair<int,int>(a.first,a.second-1),step+1));
                q.push(make_pair(pair<int,int>(a.first+1,a.second+1),step+1));
                q.push(make_pair(pair<int,int>(a.first-1,a.second-1),step+1));
            }
        }
        cout << c << endl;
    }
    return 0;
}

Measured memory_bytes: 3140