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ツづ按づァツ渉ュツ渉猟つェツ督楪達ツづつォツづ按つ「
int minArrivalCost[21][21];
// ツ幽ツ療ャツづ個暗堋督ョツδ仰ーツトツづーツ格ツ納
vector<pair<int,int> > ghostPath;
// ツ幽ツ療ャツつェツ津環嘉淞つオツつスツ湘ェツ渉環づーツ格ツ納
bool passedGhost[11][21][21];

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

// ツ渉ュツ渉猟つェツ各ツマツスツづ鳴つスツづづィツ陳つュツつスツづ淞づ個催渉ャツコツスツトツづーツ仰づ淞づゥ
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 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);
		while(1){
			bool f=false;
			for(int i = 0; i < pattern.size(); i++){
				if(passedGhost[i][cp.first][cp.second]){
					f=true;
					break;
				}
				passedGhost[i][cp.first][cp.second]=true;
				ghostPath.push_back(cp);
				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;
			}
			if(f)
				break;
		}
		int minCost=INF;
		pair<int,int> rp;
		// ツ各ツ幽ツ療ャツづ個督楪達ツポツイツδ督トツづ可づつつ「ツづ、ツ氾楪渉猟つェツ督楪達ツづつォツづつ「ツづゥツつゥツづつ、ツつゥツづーツづ敖づゥ
		for(int i = 0; i < ghostPath.size(); i++){
			cp=ghostPath[i];
			int cst=minArrivalCost[cp.first][cp.second];
			if(cst!=INF){
				// ツ渉ュツ渉猟づ個督楪達ツつェツ幽ツ療ャツづ個督楪達ツづヲツづィツ堕つゥツづつスツ湘ェツ債				if(cst<=i){
					if(minCost>i){
						rp=cp;
						minCost=min(minCost,i);
					}
				}
				// ­ÌBªHìæèx©Á½ê
				else{
					// Hìª­éÜÅÒÂ
					int cnt=cst;
					int j=(cst)%ghostPath.size();
					while(1){
						if(ghostPath[j]==cp){
							if(minCost>cnt){
								minCost=min(minCost,cnt);
								rp=cp;
							}
							break;
						}
						j=(j+1)%ghostPath.size();
						cnt++;
					}
				}
			}
		}
		if(minCost==INF)
			cout<<"impossible"<<endl;
		else{
			cout<<minCost<<" "<<rp.first<<" "<<rp.second<<endl;
		}
	}

	return 0;
}