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++: //suhan lee,saitama university

#include <vector>
#include <list>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <deque>
#include <algorithm>
#include <utility>
#include <functional>
#include <sstream>
#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <cstring>
#include <ctime>
#include <climits>
#include <cassert>
#include <complex>
using namespace std;

inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<string> vs;
typedef pair<int, int> pii;
typedef long long ll;

#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(),(a).rend()
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define rep(i,a,b) for(int i=(a);i<(b);++i)
#define repn(i,n) for(int i=0;i<n;i++)
#define EACH(t,i,c) for(t::iterator i=(c).begin(); i!=(c).end(); ++i)
#define pb push_back 
#define pf push_front
#define INF 500


void tansaku(vvi& saitanmap,int ax,int ay,int h,int w){
  saitanmap[ay][ax]=0;
  stack<pii> haba;
  int px,py;
  haba.push(make_pair(ay,ax));
  while(!haba.empty()){
   
    px=haba.top().first;
    py=haba.top().second;
    //   cout<<px<<" "<<py<<" "<<saitanmap[px][py]<<endl;
    haba.pop();
    if(px+1>=0&&px+1<h&&py>=0&&py<w )
      if(saitanmap[px][py]+1<saitanmap[px+1][py]){

      saitanmap[px+1][py]=saitanmap[px][py]+1;
      haba.push(make_pair(px+1,py));
    }
    //	cout<<"haha\n";
    if (px-1>=0&&px-1<h ) 
      if(saitanmap[px][py]+1<saitanmap[px-1][py]
      ){

      saitanmap[px-1][py]=saitanmap[px][py]+1;
      haba.push(make_pair(px-1,py));
    }
    //	cout<<"hahah\n";
    if (py+1<w ) 
      if(saitanmap[px][py]+1<saitanmap[px][py+1]
      ){

      saitanmap[px][py+1]=saitanmap[px][py]+1;
      haba.push(make_pair(px,py+1));
    }
    // cout<<"hahaha\n";
    if(py-1>=0&&py-1<w )
      if(saitanmap[px][py]+1<saitanmap[px][py-1]
        ){
	//	cout<<"hahass\n";
      saitanmap[px][py-1]=saitanmap[px][py]+1;
      haba.push(make_pair(px,py-1));
    }

  }
}
void yuurei(vvi saitanmap,string pattern,int bx,int by,int h,int w){
  int len=pattern.size();
  repn(i,INF){
    if(saitanmap[by][bx]<=i&&saitanmap[by][bx]>=0){
      cout<<i<<" "<<by<<" "<<bx<<endl;
      return;
    }
    else{
      //   cout<<i<<"not answer  "<<bx<<" "<<by<<endl;
      switch(pattern[i%len]){
      case '5':
	break;
      case '2':
	if(by<h-1)
	  by+=1;
	break;
      case '4':
	if(bx>0)
	  bx-=1;
	break;
      case '6':
	if(bx<w-1)
	  bx+=1;
	break;
      case '8':
	if(by>0)
	  by-=1;
	break;
     
      }
    }
  }
  cout<<"impossible"<<endl;
}
int main(){
  int h,w,ax,bx,ay,by;
  string maptmp,pattern;
  vvi saitanmap;
  while(true){
    cin>>h>>w;
    if(h==0&&w==0) break;
    saitanmap=vvi(h,vi(w,INF));
    repn(i,h){
      cin>>maptmp;
      repn(j,w){
	if(maptmp[j]=='A') {ax=j;ay=i;}
	else if(maptmp[j]=='B') {bx=j;by=i;}
	else if(maptmp[j]=='#') saitanmap[i][j]=-1;
	else if(maptmp[j]=='.') saitanmap[i][j]=INF;
	else {cout<<"error!"; return 0;}
      }
    }
    
    tansaku(saitanmap,ax,ay,h,w);
    cin>>pattern;
    yuurei(saitanmap,pattern,bx,by,h,w);
  }

  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>100000){
                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));
        }
    }
}