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<bits/stdc++.h>
#define P pair<int,int>
using namespace std;

int x[4]={-1,0,0,1},y[4]={0,-1,1,0};
int main(){
    int a,b;
    string s[20];
    while(cin>>a>>b,a|b){
	P n,m;
	for(int c=0;c<a;c++){cin>>s[c];
	    for(int i=0;i<b;i++){
		if(s[c][i]=='A'){n=P(c,i);s[c][i]='.';}
		else if(s[c][i]=='B'){m=P(c,i);s[c][i]='.';}
		}
	    }
	string d;cin>>d;
	int mincost[20][20];
	memset(mincost,-1,sizeof(mincost));
	queue<P>Q;
	Q.push(n);
	mincost[n.first][n.second]=0;
	while(Q.size()){
	    P t=Q.front();Q.pop();
	    for(int i=0;i<4;i++){
		int dx=t.first+x[i],dy=t.second+y[i];
		if(dx>=0&&dx<a&&dy>=0&&dy<b&&mincost[dx][dy]==-1&&s[dx][dy]=='.'){
		    mincost[dx][dy]=mincost[t.first][t.second]+1;
		    Q.push(P(dx,dy));
		    }
		}
	    }
	    int X=m.first,Y=m.second;
	for(int i=0;i<1000;i++){
	    switch(d[i%d.length()]){
		case '2':X++;break;
		case '6':Y++;break;
		case '4':Y--;break;
		case '8':X--;break;
	    }
	    if(X==a)X=a-1;
	    if(X==-1)X=0;
	    if(Y==a)Y=b-1;
	    if(Y==-1)Y=0;
	    if(mincost[X][Y]==-1)continue;
	    if(mincost[X][Y]>i)continue;
	    cout<<i<<" "<<X<<" "<<Y<<endl;
	    goto l;
	    }
	    puts("impossible");
	    l:;
	    }
    }

C++: #include<stdio.h>
#include<queue.h>
int main(){
	queue<int> q;
	int w,h,f[484],i,j,d[]={22,0,-1,0,1,0,-22},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;
				switch(getchar()){
					case'#':--f[x];break;
					case'A':a=x;break;
					case'B':b=x;break;
				}
			}
			f[i*22]=f[i*22-~w]=-9;
			getchar();
		}
		
		f[a]=t=0;
		q.push(0);
		for(q.push(a);q.size()>1;){
			a=q.front();
			q.pop();
			if(a){
				for(i=0;i<7;i+=2)
					if(f[x=a+d[i]]==-1)
						f[x]=t,
						q.push(x);
			else
				++t,q.push(0);
		}
		q.pop();
		scanf("%s",p);
		for(a=t=0;!a;){
			x=b;
			z=0;
			for(i=0;!a&&p[i];i++){
				t++;
				f[j=b+d[p[i]-'2']]>-3?b=j:0;
				f[b]>=0&&t>=f[b]?a=b:0;
				f[b]>=0&&++z;
			}
			!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++: //35
#include<iostream>
#include<algorithm>
#include<string>
#include<queue>
#include<utility>

using namespace std;

char g[20][20];
int h,w;
int t[20][20];

struct S{
  int t,x,y;
};

int main(){
  while(cin>>h>>w,h|w){
    int ax,ay,bx,by;
    for(int y=0;y<h;y++){
      for(int x=0;x<w;x++){
	cin>>g[y][x];
	if(g[y][x]=='A'){
	  ax=x;
	  ay=y;
	}else if(g[y][x]=='B'){
	  bx=x;
	  by=y;
	}
      }
    }
    fill(t[0],t[20],1<<30);
    queue<S> que;
    S is={0,ax,ay};
    que.push(is);
    while(!que.empty()){
      int x=que.front().x;
      int y=que.front().y;
      int ct=que.front().t;
      que.pop();
      if(x<0||w<=x||y<0||h<=y||t[y][x]<ct||g[y][x]=='#')continue;
      t[y][x]=ct;
      for(int i=0;i<4;i++){
	int d[]={0,1,0,-1,0};
	S ns={ct+1,x+d[i],y+d[i+1]};
	que.push(ns);
      }
    }
    string p;
    cin>>p;
    int e;
    for(e=0;e<10000;e++){
      if(t[by][bx]<=e)break;
      char o=p[e%p.size()];
      int ny=by+(o=='2')-(o=='8');
      int nx=bx+(o=='6')-(o=='4');
      if(0<=ny&&ny<h&&0<=nx&&nx<w){
	by=ny;
	bx=nx;
      }
    }
    if(e<10000){
      cout<<e<<' '<<by<<' '<<bx<<endl;
    }else{
      cout<<"impossible"<<endl;
    }
  }
  return 0;
}

C++: 4 7
A#...#B
.#.#.#.
.#.#.#.
...#...
5
4 7
A#...#B
.#.#.#.
.#.#.#.
...#...
2
4 7
A#...#B
.#.#.#.
.#.#.#.
...#...
4
4 7
A#...#B
.#.#.#.
.#.#.#.
...#...
442668
1 10
A#.......B
55555554
1 10
A#.......B
55555555
0 0