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<queue>
#include<algorithm>
using namespace std;

typedef pair<int ,int > P;
typedef pair<int, P> P2;

int v[30][30];
bool vb[30][30][20];
string g[30],L;
int h,w,s;
int ay,ax,by,bx;
int dy[] = {-1,0,1,0}, dx[] = {0,1,0,-1};

int main(){
  while(cin >> h >> w , h||w){
    for(int i=0;i<h;i++)cin >> g[i];
    cin >> L;
    s = L.size();

    for(int i=0;i<h;i++)
      for(int j=0;j<w;j++){
	if(g[i][j] == 'A'){
	  ay = i; ax = j;
	}
	if(g[i][j] == 'B'){
	  by = i; bx = j;
	}
	v[i][j] = -1;
	for(int k=0;k<s;k++)vb[i][j][k] = false;
      }

    queue<P2> q;
    v[ay][ax] = 0;
    q.push(P2(0,P(ay,ax)));

    while(!q.empty()){
      P2 p = q.front();q.pop();
 
      for(int i=0;i<4;i++){
	int sy = p.second.first + dy[i] , sx = p.second.second + dx[i];
	if(sy<0 || sx<0 || h<=sy || w<=sx)continue;
	if(v[sy][sx]>=0 || g[sy][sx]=='#')continue;
	v[sy][sx] = p.first+1;
	q.push(P2(p.first+1,P(sy,sx)));
      }
    }

    int t = 0;
    for(int i=0;i<h;i++)
      for(int j=0;j<w;j++)t = max(t,v[i][j]);

    for(int i=0;;i++){
      if(i<=t){
	if(v[by][bx]>=0 && v[by][bx]<=i){
	  cout << i << " " << by << " " << bx << endl;
	  break;
	}
      }else{
	if(v[by][bx]>=0){
	  cout << i << " " << by << " " << bx << endl;
	  break;
	}
	if(vb[by][bx][i%s]){
	  cout << "impossible\n";
	  break;
	}
      }
      vb[by][bx][i%s] = true;
      if(L[i%s] == '8' && 0<by)by--;
      if(L[i%s] == '6' && bx<w-1)bx++;
      if(L[i%s] == '2' && by<h-1)by++;
      if(L[i%s] == '4' && 0<bx)bx--;
    }
			
  }
}

C++: #include<queue>
#include<string>
#include<iostream>

#define	mp	make_pair

using namespace std;

typedef	pair<int,int>	pii;

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

int main(){
	for(int w,h;cin>>h>>w,h;){
		char grid[20][21];
		int px,py,qx,qy;
		for(int i=0;i<h;i++){
			cin>>grid[i];
			for(int j=0;j<w;j++){
				if(grid[i][j]=='A')	px=j,py=i,grid[i][j]='.';
				if(grid[i][j]=='B')	qx=j,qy=i,grid[i][j]='.';
			}
		}
		string cmd;	cin>>cmd;

		int girlcost[20][20];
		for(int i=0;i<h;i++)for(int j=0;j<w;j++)	girlcost[i][j]=1<<30;
		girlcost[py][px]=0;
		queue< pair<int,pii> > qu;	qu.push(mp(0,mp(px,py)));
		while(!qu.empty()){
			pair<int,pii> a=qu.front();	qu.pop();
			int cost=a.first,x=a.second.first,y=a.second.second;
			for(int i=0;i<4;i++){
				int xx=x+dx[i],yy=y+dy[i];
				if(0<=xx && xx<w && 0<=yy && yy<h && grid[yy][xx]!='#'){
					int nextcost=cost+1;
					if(nextcost<girlcost[yy][xx]){
						qu.push(mp(nextcost,mp(xx,yy)));
						girlcost[yy][xx]=nextcost;
					}
				}
			}
		}

		int ans=1<<30,ansx,ansy;
		int len=cmd.length();
		bool visited[20][20][10]={};
		for(int t=0,i=0;;t++,i=(i+1)%len){
			if(t>w*h && visited[qy][qx][i])	break;
			visited[qy][qx][i]=true;

			if(girlcost[qy][qx]<=t){
				ans=t;
				ansx=qx;
				ansy=qy;
				break;
			}

			switch(cmd[i]){
				case '2':	if(qy<h-1)	qy++; break;
				case '4':	if(qx>0)	qx--; break;
				case '6':	if(qx<w-1)	qx++; break;
				case '8':	if(qy>0)	qy--; break;
			}
		}

		if(ans<(1<<30))	cout<<ans<<' '<<ansy<<' '<<ansx<<endl;
		else			cout<<"impossible"<<endl;
	}

	return 0;
}