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>

using namespace std;

typedef struct {
	int x, y;
} Vector;

char map[16 + 2][16 + 2];
unsigned int data[16][16][16][16][10];
int ans;
int ans_x, ans_y;

int change(char move[], Vector mv[])
{
	int i = 0;
	while (move[i] != '\0'){
		mv[i].x = mv[i].y = 0;
		switch (move[i]){
		  case '5':
		  	break;
		  case '8':
		  	mv[i].y = -1;
			break;
		  case '6':
		  	mv[i].x = 1;
			break;
		  case '4':
		  	mv[i].x = -1;
			break;
		  case '2':
		  	mv[i].y = 1;
			break;
		}
		i++;
	}
	return (i);
}

int calc(int sx, int sy, int gx, int gy, Vector mv[], int move_count, int depth)
{
	int mx, my;
	
	
	if (map[sx][sy] == -1 || map[sx][sy] == '#' || ans <= depth){
		return (0);
	}
	if (sx == gx && sy == gy){
		if (ans > depth){
			ans = depth;
			ans_x = sx - 1;
			ans_y = sy - 1;
		}
		return (0);
	}
	if (data[sx - 1][sy - 1][gx - 1][gy - 1][depth % move_count] == 1){
		return (0);
	}
	data[sx - 1][sy - 1][gx - 1][gy - 1][depth % move_count] = 1;
	
	mx = mv[depth % move_count].x;
	my = mv[depth % move_count].y;
	
	if (map[gx + mx][gy + my] != -1){
		gx += mx;
		gy += my;
	}
	calc(sx + 1, sy, gx, gy, mv, move_count, depth + 1);
	calc(sx - 1, sy, gx, gy, mv, move_count, depth + 1);
	calc(sx, sy + 1, gx, gy, mv, move_count, depth + 1);
	calc(sx, sy - 1, gx, gy, mv, move_count, depth + 1);
	calc(sx, sy,     gx, gy, mv, move_count, depth + 1);
	
	data[sx - 1][sy - 1][gx - 1][gy - 1][depth % move_count] = 0;
	
	return (0);
}

int main(void)
{
	int hight, width;
	int sx, sy, gx, gy;
	char move[11];
	Vector mv[10];
	int move_count;
	
	while (1){
		ans = 16 * 16 * 16 * 16 * 10;
		cin >> hight >> width;
		if (hight == 0 && width == 0)break;
		for (int y = 0; y < hight + 2; y++){
			char str[16 + 1];
			if (y == 0 || y == hight + 1){
				for (int x = 0; x < width + 2; x++){
					map[x][y] = -1;
				}
			}
			else {
				cin >> str;
				map[0][y] = map[width + 1][y] = -1;
				for (int x = 0; x < width; x++){
					if (str[x] == 'A'){
						sx = x + 1;
						sy = y;
					}
					if (str[x] == 'B'){
						gx = x + 1;
						gy = y;
					}
					map[x + 1][y] = str[x];
				}
			}
		}
		cin >> move;
		memset(data, 0, 16 * 16 * 16 * 16 * 10);
		
		move_count = change(move, mv);
		
		calc(sx, sy, gx, gy, mv, move_count, 0);
		
		if (ans == 16 * 16 * 16 * 16 * 10){
			cout << "impossible" << endl;
		}
		else {
			cout << ans << ' ' << ans_y << ' ' << ans_x << endl;
		}
	}
	
	return (0);
}

C++: #include<iostream>
#include<algorithm>
#include<climits>
#include<vector>
#include<queue>
#include<stack>
#include<cmath>
#include<string.h>

using namespace std;

int h,w,sx,sy,gx,gy;
int dx[4]={1,0,-1,0};
int dy[4]={0,-1,0,1};

char ma[21][21];
int co[21][21];
bool visited[21][21];

int main(){
    while(cin>>h>>w,h){
        for(int i=0;i<h;i++){
            for(int j=0;j<w;j++){
                co[i][j]=INT_MAX;
                cin>>ma[i][j];
                if(ma[i][j]=='A'){
                    sx=j,sy=i;
                } else if(ma[i][j]=='B'){
                    gx=j,gy=i;
                }
            }
        }
        queue<pair<pair<int,int>,int> >q;
        q.push(make_pair(make_pair(sx, sy), 0));
        while(q.size()){
            pair<pair<int,int>,int> p = q.front();
            if(co[p.first.second][p.first.first]!=INT_MAX){
                continue;
            }
            co[p.first.second][p.first.first]=p.second;
            q.pop();
            for(int i=0;i<4;i++){
                int nx=p.first.first+dx[i];
                int ny=p.first.second+dy[i];
                if(nx>=0&&nx<w&&ny>=0&ny<h&&ma[ny][nx]!='#'&&co[ny][nx]==INT_MAX){
                    q.push(make_pair(make_pair(nx, ny), p.second+1));
                }
            }
        }
        string pat;
        cin>>pat;
//        int go=0;
//        for(int j=0;;j++){
//            int i=j%pat.length();
//         //   cout<<gy<<" "<<gx<<" "<<co[gy][gx]<<" "<<INT_MAX<<endl;
//            if(co[gy][gx]<=go){
//                cout<<go<<" "<<gy<<" "<<gx<<endl;
//                break;
//            }
//            if(go>1000){
//                cout<<"impossible"<<endl;
//                break;
//            }
//            if(pat[i]=='5'){
//                
//            } else 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,gy);
//            gy=min(h-1,gy);
//            gx=max(0,gx);
//            gx=min(w-1,gx);
//            go++;
//        }
    }
}