using namespace std;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n, k;
    cin >> n >> k;
    vector<vector<char>> lit(n, vector<char>(n, 0));
    for (int i = 0; i < k; ++i) {
        int x, y;
        cin >> x >> y;
        --x; --y;
        for (int dx = -1; dx <= 1; ++dx)
            for (int dy = -1; dy <= 1; ++dy) {
                int nx = x + dx, ny = y + dy;
                if (0 <= nx && nx < n && 0 <= ny && ny < n)
                    lit[nx][ny] = 1;
            }
    }
    long long cnt = 0;
    for (int i = 0; i < n; ++i)
        cnt += count(lit[i].begin(), lit[i].end(), 1);
    cout << (long long)n * n - cnt << '\n';
    return 0;
}

MC好评