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

typedef pair<int,int> P;

int main(){
  int h,w;
  string g[30],p;
  bool vis[30][30][30];
  int t[30][30];

  while(cin >> h >> w , h||w){
    int ay,ax,by,bx;
    for(int i=0;i<h;i++){
      cin >> g[i];
      for(int j=0;j<w;j++){
	if(g[i][j] == 'A'){ay = i; ax = j; g[i][j] = '.';}
	if(g[i][j] == 'B'){by = i; bx = j; g[i][j] = '.';}
	t[i][j] = -1;
	for(int k=0;k<10;k++)vis[i][j][k] = false;
      }
    }

    cin >> p;
    int s = p.size();

    t[ay][ax] = 0;
    queue<P> q;
    q.push(P(ay,ax));
    int m;

    while(q.size()){
      P p = q.front();q.pop();
      int dy[] = {-1,0,1,0}, dx[] = {0,1,0,-1};

      for(int i=0;i<4;i++){
	int ty = p.first + dy[i], tx = p.second + dx[i];
	if(ty<0 || tx<0 || h<=ty || w<=tx || g[ty][tx] == '#')continue;
	if(t[ty][tx]<0){
	  m = t[ty][tx] = t[p.first][p.second] + 1;
	  q.push(P(ty,tx));
	}
      }
    }

    int cnt = 0;
    bool f = false;
    for(;;){
      if(vis[by][bx][cnt%s] && m+s<cnt)break;
      vis[by][bx][cnt%s] = true;
      if(p[cnt%s]=='8' && 0<by)by--;
      if(p[cnt%s]=='6' && bx<w-1)bx++;
      if(p[cnt%s]=='4' && 0<bx)bx--;
      if(p[cnt%s]=='2' && by<h-1)by++;
      cnt++;
      if(0<=t[by][bx] && t[by][bx]<=cnt){
	cout << cnt << " " << by << " " << bx << endl;
	f = true;
	break;
      }
    }
    if(!f)cout << "Impossible\n";
  }
}

C++: #include <iostream>
#include <complex>
#include <sstream>
#include <string>
#include <algorithm>
#include <deque>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <vector>
#include <set>
#include <limits>
#include <cstdio>
#include <cctype>
#include <cmath>
#include <cstring>
#include <cstdlib>
#include <ctime>
using namespace std;
#define REP(i, j) for(int i = 0; i < (int)(j); ++i)
#define FOR(i, j, k) for(int i = (int)(j); i < (int)(k); ++i)
#define SORT(v) sort((v).begin(), (v).end())
#define REVERSE(v) reverse((v).begin(), (v).end())
typedef complex<double> P;
const int INF = 1e5;

int H, W;
int my[] = {0, 0, 1, -1};
int mx[] = {1, -1, 0, 0};

void dfsA(int t, int y, int x, vector<string> &v, vector< vector<int> > &cnt){
  REP(i, 4){
    int ny = y + my[i], nx = x + mx[i];
    if(ny >= 0 && nx >= 0 && ny < H && nx < W && v[ny][nx] != '#' && cnt[ny][nx] > t + 1){
      cnt[ny][nx] = t + 1;
      dfsA(t + 1, ny, nx, v, cnt);
    }
  }
}

int main() {
  while(cin >>H >>W && H){
    vector<string> v(H); REP(i, H) cin >>v[i];
    vector< vector<int> > cntA(H, vector<int>(W, INF));
    REP(i, H) REP(j, W) if(v[i][j] == 'A') { cntA[i][j] = 0; dfsA(0, i, j, v, cntA); }
    string pattern; cin >>pattern;
    int y, x, ay, ax, ans = INF, pl = pattern.length();
    REP(i, H) REP(j, W) if(v[i][j] == 'B') { y = i; x = j; }
    REP(i, INF){
      if(cntA[y][x] <= i) { ans = i; ay = y; ax = x; break; }
      //cout <<y <<", " <<x <<", " <<cntA[y][x] <<", " <<i <<endl;
      if(pattern[i % pl] == '8') { y = max(0, y - 1); }
      else if(pattern[i % pl] == '6') { x = min(W - 1, x + 1); }
      else if(pattern[i % pl] == '4') { x = max(0, x - 1); }
      else if(pattern[i % pl] == '2') { y = min(H - 1, y + 1); }
    }
    if(ans == INF) cout <<"impossible" <<endl;
    else cout <<ans <<" " <<ay <<" " <<ax <<endl;
  }
  return 0;
}