Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
	)

var scanner = bufio.NewScanner(os.Stdin)

const INF = 0x7FFFFFFF

var (
	direction1 = [][]int{ // 奇数段目の移動方向
		{-1, 0}, {1, 0}, {0, -1}, {0, 1}, {1, -1}, {1, 1},
	}
	direction2 = [][]int{ // 偶数段目の移動方向
		{-1, -1}, {0, -1}, {1, 0}, {0, 1}, {-1, 1}, {-1, 0},
	}
)

func main() {
	for scanner.Scan() {
		buf := strings.Split(scanner.Text(), " ")
		m, _ := strconv.Atoi(buf[0])
		n, _ := strconv.Atoi(buf[1])
		if m == 0 && n == 0 {
			break
		}
		// initialize district_map
		/*
			district_map = [
				[-1, -1,  -1,  -1,  -1]
				[-1, INF, INF, INF, -1]
				[-1, INF, INF, INF, -1]
				[-1, INF, INF, INF, -1]
				[-1, INF, INF, INF, -1]
				[-1, -1,  -1,  -1,  -1]
			]
		*/
		district_map := make([][]int, n+2)
		for i := range district_map {
			district_map[i] = make([]int, m+2)
		}
		tmp1 := make([]int, m+2)
		for i := range tmp1 {
			tmp1[i] = -1
		}
		district_map[0] = tmp1
		district_map[n+1] = tmp1
		for i := 1; i < n+1; i++ {
			district_map[i] = make([]int, m+2)
			district_map[i][0] = -1
			district_map[i][m+1] = -1
			for j := 1; j < m+1; j++ {
				district_map[i][j] = INF
			}
		}

		scanner.Scan()
		s, _ := strconv.Atoi(scanner.Text())
		for i := 0; i < s; i++ {
			scanner.Scan()
			buf_ := strings.Split(scanner.Text(), " ")
			x, _ := strconv.Atoi(buf_[0])
			y, _ := strconv.Atoi(buf_[1])
			Search(Point{x, y}, district_map, m, n)
		}
		ans := 0
		scanner.Scan()
		t, _ := strconv.Atoi(scanner.Text())
		for i := 0; i < t; i++ {
			scanner.Scan()
			buf__ := strings.Split(scanner.Text(), " ")
			x, _ := strconv.Atoi(buf__[0])
			y, _ := strconv.Atoi(buf__[1])
			z := Count(Point{x, y}, district_map, m, n)
			ans = max(ans, z)
		}
		fmt.Println(ans)
	}
}

func max(a, b int) int {
	if a < b {
		return b
	}
	return a
}

type Point struct {
	x, y int
}

type Entry struct {
	hop   int
	point Point
}

func Search(p Point, mp [][]int, m, n int) {
	que := make([]Entry, 0)
	que = append(que, Entry{0, p})
	check := make([][]bool, n+2)
	for i := range check {
		check[i] = make([]bool, m+2)
	}
	check[p.y][p.x] = true
	mp[p.y][p.x] = 0
	var direction [][]int
	for len(que) > 0 {
		tmp := que[0]
		que = que[1:]
		dist, point := tmp.hop, tmp.point
		if point.y%2 == 0 {
			direction = direction1
		} else {
			direction = direction2
		}
		for _, d := range direction {
			nx, ny := point.x+d[0], point.y+d[1]
			if !check[ny][nx] && mp[ny][nx] != -1 {
				check[ny][nx] = true
				if mp[ny][nx] > dist+1 {
					mp[ny][nx] = dist + 1
				}
				que = append(que, Entry{dist + 1, Point{nx, ny}})
			}
		}
	}
}

func Count(p Point, mp [][]int, m, n int) int {
	que := make([]Entry, 0)
	que = append(que, Entry{0, p})
	check := make([][]bool, n+2)
	for i := range check {
		check[i] = make([]bool, m+2)
	}
	check[p.y][p.x] = true
	ans := 1
	var direction [][]int
	for len(que) > 0 {
		tmp := que[0]
		que = que[1:]
		dist, point := tmp.hop, tmp.point
		if point.y%2 == 0 {
			direction = direction1
		} else {
			direction = direction2
		}
		for _, d := range direction {
			nx, ny := point.x+d[0], point.y+d[1]
			if !check[ny][nx] && mp[ny][nx] != -1 {
				check[ny][nx] = true
				if mp[ny][nx] > dist+1 {
					ans++
				}
				que = append(que, Entry{dist + 1, Point{nx, ny}})
			}
		}
	}
	return ans
}

C++: #include <iostream>
#include <sstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <climits>
#include <cfloat>
using namespace std;

int main()
{
    for(;;){
        int m, n, s;
        cin >> m >> n >> s;
        if(m == 0)
            return 0;

        vector<vector<int> > dist(n, vector<int>(m, INT_MAX));
        for(int i=0; i<s; ++i){
            int x, y;
            cin >> x >> y;
            -- x;
            -- y;

            for(int j=0; j<n; ++j){
                for(int k=0; k<m; ++k){
                    int dy = abs(y - j);
                    int dx = abs(x - k);
                    dist[j][k] = min(dist[j][k], max(dy, dx));
                }
            }
        }

        int t;
        cin >> t;

        int ret = 0;
        for(int i=0; i<t; ++i){
            int x, y;
            cin >> x >> y;
            -- x;
            -- y;

            int num = 0;
            for(int j=0; j<n; ++j){
                for(int k=0; k<m; ++k){
                    int dy = abs(y - j);
                    int dx = abs(x - k);
                    if(max(dy, dx) < dist[j][k])
                        ++ num;
                }
            }
            ret = max(ret, num);
        }

        cout << ret << endl;
    }
}

C++: #include <iostream>
#include <sstream>
#include <string>
#include <algorithm>
#include <vector>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <cassert>

using namespace std;

#define FOR(i,k,n) for(int i=(k); i<(int)(n); ++i)
#define REP(i,n) FOR(i,0,n)
#define FORIT(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i)

template<class T> void debug(T begin, T end){ for(T i = begin; i != end; ++i) cerr<<*i<<" "; cerr<<endl; }
inline bool valid(int x, int y, int W, int H){ return (x >= 0 && y >= 0 && x < W && y < H); }

typedef long long ll;
const int INF = 100000000;
const double EPS = 1e-8;
const int MOD = 1000000007;
int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};
typedef pair<int, int> P;
int distance6[200][200];
void bfs(){
  const int W = 110;
  const int H = 110;
  REP(y, H) REP(x, W) distance6[y][x] = INF;
  queue<int> qx, qy;
  qx.push(0); qy.push(0);
  distance6[0][0] = 0;
  while(!qx.empty()){
    int x = qx.front(); qx.pop();
    int y = qy.front(); qy.pop();
    if(y % 2 == 0){
      int dx[6] = {-1, 0, 1, 0, -1, -1};
      int dy[6] = {-1, -1, 0, 1, 1, 0};
      REP(r, 6) {
        int nx = x + dx[r];
        int ny = y + dy[r];
        if(valid(nx, ny, W, H) && distance6[ny][nx] > distance6[y][x] + 1){
          distance6[ny][nx] = distance6[y][x] + 1;
          qx.push(nx); qy.push(ny);
        }
      }
    }else{
      int dx[6] = {0, 1, 1, 1, 0, -1};
      int dy[6] = {-1, -1, 0, 1, 1, 0};
      REP(r, 6) {
        int nx = x + dx[r];
        int ny = y + dy[r];
        if(valid(nx, ny, W, H) && distance6[ny][nx] > distance6[y][x] + 1){
          distance6[ny][nx] = distance6[y][x] + 1;
          qx.push(nx); qy.push(ny);
        }
      }
    }
  }
}
int dist(int x1, int y1, int x2, int y2){
  int x = abs(x2 - x1);
  int y = abs(y2 - y1);
  return distance6[y][x];
}

int main(){
  bfs();
  int W, H;
  while(cin >> W >> H && W){
    int N;
    int tx[10], ty[10];
    cin >> N;
    REP(i, N) cin >> tx[i] >> ty[i];
    int ans = 0;
    int M; cin >> M;
    REP(i, M){
      int nx, ny; cin >> nx >> ny;
      int cnt = 0;
      REP(y, H)REP(x, W){
        int d = dist(nx, ny, x, y);
        bool ok = true;
        REP(j, N) if(dist(tx[j], ty[j], x, y) <= d) ok = false;
        if(ok) cnt++;
      }
      ans = max(ans, cnt);
    }
    cout << ans << endl;
  }
  return 0;
}