Go: package main

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

func configure(scanner *bufio.Scanner) {
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 1000005), 1000005)
}
func getNextString(scanner *bufio.Scanner) string {
	scanned := scanner.Scan()
	if !scanned {
		panic("scan failed")
	}
	return scanner.Text()
}
func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}
func getNextInt64(scanner *bufio.Scanner) int64 {
	i, _ := strconv.ParseInt(getNextString(scanner), 10, 64)
	return i
}
func getNextFloat64(scanner *bufio.Scanner) float64 {
	i, _ := strconv.ParseFloat(getNextString(scanner), 64)
	return i
}
func main() {
	fp := os.Stdin
	wfp := os.Stdout
	extra := 0
	if os.Getenv("I") == "IronMan" {
		fp, _ = os.Open(os.Getenv("END_GAME"))
		extra = 100
	}
	scanner := bufio.NewScanner(fp)
	configure(scanner)
	writer := bufio.NewWriter(wfp)
	defer func() {
		r := recover()
		if r != nil {
			fmt.Fprintln(writer, r)
		}
		writer.Flush()
	}()
	solve(scanner, writer)
	for i := 0; i < extra; i++ {
		fmt.Fprintln(writer, "-----------------------------------")
		solve(scanner, writer)
	}
}
func solve(scanner *bufio.Scanner, writer *bufio.Writer) {
	dy := [4]int{-1, 0, 0, 1}
	dx := [4]int{0, -1, 1, 0}
	for {
		h := getNextInt(scanner)
		w := getNextInt(scanner)
		if h == 0 {
			break
		}
		grid := makeGrid(h, w)
		a := [2]int{}
		b := [2]int{}
		for i := 0; i < h; i++ {
			s := getNextString(scanner)
			for j := 0; j < w; j++ {
				if s[j] == '#' {
					grid[i][j] = math.MaxInt32
					continue
				}
				if s[j] == 'A' {
					a[0] = i
					a[1] = j
					continue
				}
				if s[j] == 'B' {
					b[0] = i
					b[1] = j
				}
				grid[i][j] = math.MaxInt32 - 1
			}
		}
		q := make([][2]int, 0)
		q = append(q, a)
		for len(q) > 0 {
			p := q[0]
			q = q[1:]
			for i := 0; i < 4; i++ {
				yy := p[0] + dy[i]
				xx := p[1] + dx[i]
				if yy == a[0] && xx == a[1] {
					continue
				}
				if yy < 0 || yy >= h {
					continue
				}
				if xx < 0 || xx >= w {
					continue
				}
				if grid[yy][xx] == math.MaxInt32 {
					continue
				}
				if grid[yy][xx] <= grid[p[0]][p[1]]+1 {
					continue
				}
				grid[yy][xx] = grid[p[0]][p[1]] + 1
				q = append(q, [2]int{yy, xx})
			}
		}
		move := getNextString(scanner)
		i := 0
		m := len(move)
		for {
			if i > 400 {
				fmt.Fprintln(writer, "impossible")
				break
			}
			if grid[b[0]][b[1]] <= i {
				fmt.Fprintln(writer, fmt.Sprintf("%d %d %d", i, b[0], b[1]))
				break
			}
			switch move[i%m] {
			case '8':
				if b[0] > 0 {
					b[0]--
				}
			case '6':
				if b[1]+1 < w {
					b[1]++
				}
			case '4':
				if b[1] > 0 {
					b[1]--
				}
			case '2':
				if b[0]+1 < h {
					b[0]++
				}
			}
			i++
		}
	}
}
func makeGrid(h, w int) [][]int {
	index := make([][]int, h, h)
	data := make([]int, h*w, h*w)
	for i := 0; i < h; i++ {
		index[i] = data[i*w : (i+1)*w]
	}
	return index
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <queue>
#include <set>

using namespace std;

int h,w;
char field[21][21];

const int INF=100000000;

// INFÈç­ªBÅ«È¢
int minArrivalCost[21][21];
// HìÌÚ®[gði[
vector<pair<int,int> > ghostPath;
// HìªÊßµ½êði[
bool passedGhost[11][21][21];

const int dy[]={-1,0,0,1};
const int dx[]={0,-1,1,0};

// ­ªe}XÖ½Çè­½ßÌÅ¬RXgðßé
void bfs(int sx,int sy){
	queue<pair<int,int> > *prv=new queue<pair<int,int> > ();
	queue<pair<int,int> > *nxt=new queue<pair<int,int> > ();
	prv->push(make_pair(sy,sx));

	bool passed[21][21];
	for(int i = 0; i < 21; i++){
		for(int j = 0; j < 21; j++){
			passed[i][j]=false;
		}
	}
	int cnt=0;
	while(prv->size()){
		while(prv->size()){
			pair<int,int> cp=prv->front();prv->pop();
			if(passed[cp.first][cp.second])
				continue;
			passed[cp.first][cp.second]=true;
			minArrivalCost[cp.first][cp.second]=min(minArrivalCost[cp.first][cp.second],cnt);
			for(int i = 0; i < 4; i++){
				pair<int,int> np=cp;
				np.first+=dy[i];
				np.second+=dx[i];
				if(np.first>=0&&np.second>=0&&np.first<h&&np.second<w){
					if(!passed[np.first][np.second]&&field[np.first][np.second]!='#'){
						nxt->push(np);
					}
				}
			}
		}
		cnt++;
		swap(prv,nxt);
	}

	delete prv,nxt;
}

int searchGhost(pair<int,int> cp,int tern,string pattern,pair<int,int> sp){
	// 500ñ®¢Äàoï¦È¢ÈçÎA-1ðÔ·B»¤ÅÈ¯êÎAoï¦éÅ¬^[ðÔ·
	int cnt=-1;
	while(1){
		bool f=false;
		for(int i = 0; i < pattern.size(); i++){
			cnt++;
			if(cnt==300)
				return -1;
			// ­ÌÊuÉBµ½ê
			if(sp==cp){
				if(tern<=cnt){
					return cnt;
				}
			}
			char c = pattern[i];
			pair<int,int> np=cp;
			
			if(c=='8')
				np.first-=1;
			else if(c=='6')
				np.second+=1;
			else if(c=='4')
				np.second-=1;
			else if(c=='2')
				np.first++;
			
			if(np.first<0)
				np.first=0;
			else if(np.first>=h)
				np.first=h-1;
			else if(np.second>=w)
				np.second=w-1;
			else if(np.second<0)
				np.second=0;
			cp=np;
		}
	}
}

int main(){

	while(cin>>h>>w&&!(h==0&&w==0)){
		ghostPath.clear();
		for(int i = 0; i < 21; i++){
			for(int j = 0; j < 21; j++){
				for(int k = 0; k < 11; k++){
					passedGhost[k][i][j]=false;
				}
				minArrivalCost[i][j]=INF;
			}
		}
		int sx,sy;
		int gx,gy;
		for(int i = 0; i < h; i++){
			for(int j = 0; j < w; j++){
				cin>>field[i][j];
				if(field[i][j]=='A'){
					sx=j;
					sy=i;
				}
				else if(field[i][j]=='B'){
					gx=j;
					gy=i;
				}
			}
		}
		string pattern;
		cin>>pattern;
		bfs(sx,sy);

		pair<int,int> cp=make_pair(gy,gx);
		int minCost=INF;
		pair<int,int> rp;
		// eHìÌB|CgÉÂ¢ÄAÞªBÅ«Ä¢é©Ç¤©ðÝé
		for(int i = 0; i < h; i++){
			for(int j = 0; j < w; j++){
				cp=make_pair(i,j);
				int cst=minArrivalCost[cp.first][cp.second];
				if(cst!=INF){
					int r=searchGhost(make_pair(gy,gx),cst,pattern,cp);
					if(r!=-1){
						if(minCost>r){
							minCost=min(minCost,r);
							rp=cp;
						}
					}
				}
			}
		}
		if(minCost==INF)
			cout<<"impossible"<<endl;
		else{
			cout<<minCost<<" "<<rp.first<<" "<<rp.second<<endl;
		}
	}

	return 0;
}

C++: #include<iostream>
#include<queue>
using namespace std;
typedef pair<pair<int,int>,int> pa;
#define ff first.first
#define fs first.second

int h,w,sx,sy,gx,gy;
int dx[4]={1,0,-1,0};
int dy[4]={0,-1,0,1};
int co[21][21];
char ma[21][21];
bool visited[21][21];
string pat;
int m = 999999;

int main(){
    while(cin>>h>>w,h){
        for(int i=0;i<h;i++){
            for(int j=0;j<w;j++){
                co[i][j]=m;
                cin>>ma[i][j];
                if(ma[i][j]=='A')
                    sx=j,sy=i;
                else if(ma[i][j]=='B')
                    gx=j,gy=i;
            }
        }
        queue<pa>q;
        q.push(make_pair(make_pair(sx, sy), 0));
        while(q.size()){
            pa p = q.front();
            q.pop();
            if(co[p.fs][p.ff]!=m)
                continue;
            co[p.fs][p.ff]=p.second;
            for(int i=0;i<4;i++){
                int nx=p.ff+dx[i];
                int ny=p.fs+dy[i];
                if(nx>=0&&nx<w&&ny>=0&ny<h&&ma[ny][nx]!='#'&&co[ny][nx]==m)
                    q.push(make_pair(make_pair(nx, ny), p.second+1));
            }
        }
        cin>>pat;
        for(int j=0,go=0;;j++,go++){
            int i=j%pat.length();
            if(co[gy][gx]<=go){
                cout<<go<<" "<<gy<<" "<<gx<<endl;
                break;
            }
            if(go>100){
                cout<<"impossible"<<endl;
                break;
            }
            if(pat[i]=='8')
                gy--;
            else if(pat[i]=='6')
                gx++;
            else if(pat[i]=='4')
                gx--;
            else if(pat[i]=='2')
                gy++;
            gy=max(0,min(h-1,gy));
            gx=max(0,min(w-1,gx));
        }
    }
}