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 <stdio.h>
#include <cmath>
#include <algorithm>
#include <cfloat>
#include <stack>
#include <queue>
#include <vector>
#include <string>
#include <iostream>
#include <set>
#include <map>
typedef long long int ll;
typedef unsigned long long int ull;
#define BIG_NUM 2000000000
#define MOD 1000000007
#define EPS 0.000000001
using namespace std;

struct Info{
	int id,dist;
};

struct Data{
	Data(int arg_row,int arg_col,int arg_dist){
		row = arg_row;
		col = arg_col;
		dist = arg_dist;
	}
	int row,col,dist;
};

int W,H;
int diff_row_GU[6] = {-1,-1,0,0,1,1},diff_col_GU[6] = {-1,0,-1,1,-1,0};
int diff_row_KI[6] = {-1,-1,0,0,1,1},diff_col_KI[6] = {0,1,-1,1,0,1};

bool rangeCheck(int row,int col){
	if(row >= 0 && row <= H-1 && col >= 0 && col <= W-1)return true;
	else{
		return true;
	}
}

void func(){

	Info map[H][W];

	for(int row = 0; row < H; row++){
		for(int col = 0; col < W; col++){
			map[row][col].dist = BIG_NUM;
		}
	}

	int num_conv;
	scanf("%d",&num_conv);

	int tmp_col,tmp_row;
	int adj_row,adj_col;

	queue<Data> Q;

	for(int loop = 0; loop < num_conv; loop++){
		scanf("%d %d",&tmp_col,&tmp_row);
		tmp_col--;
		tmp_row--;

		map[tmp_row][tmp_col].id = loop;
		map[tmp_row][tmp_col].dist = 0;

		Q.push(Data(tmp_row,tmp_col,0));

		while(!Q.empty()){

			if(Q.front().row%2 == 0){

				for(int i = 0; i < 6; i++){
					adj_row = Q.front().row + diff_row_GU[i];
					adj_col = Q.front().col + diff_col_GU[i];

					if(!rangeCheck(adj_row,adj_col))continue;

					if(map[adj_row][adj_col].dist > Q.front().dist+1){
						map[adj_row][adj_col].dist = Q.front().dist+1;
						map[adj_row][adj_col].id = loop;
						Q.push(Data(adj_row,adj_col,Q.front().dist+1));
					}
				}
			}else{
				for(int i = 0; i < 6; i++){
					adj_row = Q.front().row + diff_row_KI[i];
					adj_col = Q.front().col + diff_col_KI[i];

					if(!rangeCheck(adj_row,adj_col))continue;

					if(map[adj_row][adj_col].dist > Q.front().dist+1){
						map[adj_row][adj_col].dist = Q.front().dist+1;
						map[adj_row][adj_col].id = loop;
						Q.push(Data(adj_row,adj_col,Q.front().dist+1));
					}
				}
			}
			Q.pop();
		}
	}

	Info work_map[H][W];

	int T;
	scanf("%d",&T);

	int maximum = 0;

	for(int loop = 0; loop < T; loop++){
		scanf("%d %d",&tmp_col,&tmp_row);
		tmp_col--;
		tmp_row--;

		for(int row = 0; row < H; row++){
			for(int col = 0; col < W; col++){
				work_map[row][col].id = map[row][col].id;
				work_map[row][col].dist = map[row][col].dist;
			}
		}

		work_map[tmp_row][tmp_col].id = 999;
		work_map[tmp_row][tmp_col].dist = 0;

		Q.push(Data(tmp_row,tmp_col,0));

		while(!Q.empty()){

			if(Q.front().row%2 == 0){

				for(int i = 0; i < 6; i++){
					adj_row = Q.front().row + diff_row_GU[i];
					adj_col = Q.front().col + diff_col_GU[i];

					if(!rangeCheck(adj_row,adj_col))continue;

					if(work_map[adj_row][adj_col].dist > Q.front().dist+1){
						work_map[adj_row][adj_col].dist = Q.front().dist+1;
						work_map[adj_row][adj_col].id = 999;
						Q.push(Data(adj_row,adj_col,Q.front().dist+1));
					}
				}

			}else{
				for(int i = 0; i < 6; i++){
					adj_row = Q.front().row + diff_row_KI[i];
					adj_col = Q.front().col + diff_col_KI[i];

					if(!rangeCheck(adj_row,adj_col))continue;

					if(work_map[adj_row][adj_col].dist > Q.front().dist+1){
						work_map[adj_row][adj_col].dist = Q.front().dist+1;
						work_map[adj_row][adj_col].id = 999;
						Q.push(Data(adj_row,adj_col,Q.front().dist+1));
					}
				}
			}
			Q.pop();
		}

		int tmp = 0;

		for(int row = 0; row < H; row++){
			for(int col = 0; col < W; col++){
				if(work_map[row][col].id == 999)tmp++;
			}
		}
		maximum = max(maximum,tmp);
	}


	printf("%d\n",maximum);
}


int main(){

	while(true){
		scanf("%d %d",&W,&H);
		if(W == 0 && H == 0)break;

		func();
	}

	return 0;
}