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 <cstdio>
#include <cstdint>
#include <algorithm>
#include <vector>
#include <string>
#include <queue>

const size_t di[]={size_t(-1), 0, 1, 0};
const size_t dj[]={0, size_t(-1), 0, 1};
const int INF=1e9;
const size_t dti[]={0, 0, 1, 0, 0, 0, 0, 0, size_t(-1)};
const size_t dtj[]={0, 0, 0, 0, size_t(-1), 0, 1, 0, 0};

int testcase_ends() {
  size_t H, W;
  scanf("%zu %zu", &H, &W);

  if (H == 0 && W == 0)
    return 1;

  std::vector<std::string> s(H);
  size_t si=-1, sj=-1;
  size_t ti=-1, tj=-1;
  for (size_t i=0; i<H; ++i) {
    char buf[128];
    scanf("%s", buf);
    s[i] = buf;
    for (size_t j=0; j<W; ++j) {
      if (s[i][j] == 'A') {
        si = i;
        sj = j;
      } else if (s[i][j] == 'B') {
        ti = i;
        tj = j;
      }
    }
  }

  char buf[128];
  scanf("%s", buf);
  std::string t=buf;

  std::queue<std::pair<size_t, size_t>> q;
  q.emplace(si, sj);
  std::vector<std::vector<int>> dp(H, std::vector<int>(W, INF));
  dp[si][sj] = 0;
  while (!q.empty()) {
    std::pair<size_t, size_t> p=q.front();
    q.pop();
    size_t i=p.first, j=p.second;
    for (size_t k=0; k<4; ++k) {
      size_t ni=i+di[k], nj=j+dj[k];
      if (!(ni < H && nj < W)) continue;
      if (s[ni][nj] == '#') continue;
      if (dp[ni][nj] <= dp[i][j] + 1) continue;
      dp[ni][nj] = dp[i][j] + 1;
      q.emplace(ni, nj);
    }
  }

  // for (size_t i=0; i<H; ++i)
  //   for (size_t j=0; j<W; ++j)
  //     if (dp[i][j] < INF)
  //       printf("%d%c", dp[i][j], j+1<W? ' ':'\n');
  //     else
  //       printf("#%c", j+1<W? ' ':'\n');

  size_t tlen=t.length();
  std::pair<size_t, size_t> res(-1, -1);
  int tt=INF;
  for (int i=0; i<1000; ++i) {
    size_t nti=ti+dti[t[i%tlen]-'0'];
    size_t ntj=tj+dtj[t[i%tlen]-'0'];
    if (nti < H) ti = nti;
    if (ntj < W) tj = ntj;
    if (dp[ti][tj] < INF) {
      if (dp[ti][tj] > i+1) continue;
      if (i+1 < tt) {
        tt = i+1;
        res = {ti, tj};
      }
    }
  }
  if (tt < INF)
    return !printf("%d %zu %zu\n", tt, res.first, res.second);
  printf("impossible\n");
  return 0;
}

int main() {
  while (!testcase_ends()) {}
}

C++: #import<stdio.h>
#import<queue>
int main(){std::queue<int>q;int w,h,f[484],i,j,a,b,t,x,z;char p[15];for(;scanf("%d%d ",&h,&w),h;){for(j=0;j<w+2;j++)f[j]=f[j-~h*22]=-9;for(i=1;i<=h;i++){for(j=1;j<=w;j++)f[x=i*22+j]=-1,z=getchar(),z-35?z>65?b=x:z>64?a=x:1:--f[x];f[i*22]=f[i*22-~w]=-9;getchar();}f[a]=t=0;q.push(0);for(q.push(a);a=q.front(),q.size()>1;q.pop())if(!a)++t,q.push(0);else for(i=4;i--;)if(f[x=a+" 57L"[i]-54]==-1)f[x]=t,q.push(x);q.pop();scanf("%s",p);for(a=t=0;!a;){x=b;z=0;for(i=0;!a&&p[i];f[b]>=0&&++z){++t,f[j=b-54+"L65676 "[p[i++]-50]]>-3?b=j:0,f[b]>=0&t>=f[b]?a=b:0;!z&!a&!p[i]&b==x&f[b]<0&&--a;}printf(a<0?"impossible\n":"%d %d %d\n",t,a/22-1,a%22-1);}}

C++: #include <cstdio>
#include <algorithm>
#include <queue>
#include <utility>
#include <cstring>
using namespace std;

#define mp make_pair

typedef pair<int, int> P;
struct Node {
	P a, b;
	int cnt;
	Node(P a, P b, int cnt) : a(a), b(b), cnt(cnt) {}
};

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

int conv(char c) {
	int ret;
	switch(c) {
		case '6': ret = 0; break;
		case '2': ret = 1; break;
		case '4': ret = 2; break;
		case '8': ret = 3; break;
		case '5': ret = 4; break;
	}
	return ret;
}

char field[20][21];

int main() {
	for(int H, W; ~scanf("%d%d", &H, &W), H || W;) {
		P a_fst, b_fst;

		for(int y = 0; y < H; y++) {
			scanf(" %s", field[y]);
			for(int x = 0; x < W; x++) {
				if(field[y][x] == 'A') {
					a_fst = mp(y, x);
					field[y][x] = '.';
				}
				if(field[y][x] == 'B') {
					b_fst = mp(y, x);
					field[y][x] = '.';
				}
			}
		}
		
		char goast[11];
		int gsize;
		scanf(" %s", goast);
		gsize = strlen(goast);

		queue<Node> Q;
		Q.push(Node(a_fst, b_fst, 0));

		bool done[20][20][20][20][10]; // a.y, a.x, b.y, b.x, goast_command_number
		memset(done, 0, sizeof done);

		Node answer = Node(a_fst, b_fst, -1);

		while(!Q.empty()) {
			Node now = Q.front(); Q.pop();
			P a = now.a, b = now.b;
			if(a.first == b.first && a.second == b.second) {
				answer = now;
				break;
			}
			for(int i = 0; i < 5; i++) {
				int nay = a.first + dy[i];
				int nax = a.second + dx[i];
				int nby = b.first + dy[conv(goast[now.cnt % gsize])];
				int nbx = b.second + dx[conv(goast[now.cnt % gsize])];

				if(!(0 <= nay && nay < H && 0 <= nax && nax < W)) continue;
				if(!(0 <= nby && nby < H && 0 <= nbx && nbx < W)) {
					nby = b.first;
					nbx = b.second;
				}
				if(field[nay][nax] != '#' && done[nay][nax][nby][nbx][now.cnt % gsize] == false) {
					done[nay][nax][nby][nbx][now.cnt % gsize] = true;
					Q.push(Node(mp(nay, nax), mp(nby, nbx), now.cnt + 1));
				}
			}
		}

		if(answer.cnt == -1) {
			puts("impossible");
		} else {
			printf("%d %d %d\n", answer.cnt, answer.a.first, answer.a.second);
		}
	}
	return 0;
}