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<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;
                }
            }
        }
        memset(visited, 0, sizeof(visited));
        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(visited[p.first.second][p.first.first]){
                continue;
            }
            visited[p.first.second][p.first.first]=1;
            co[p.first.second][p.first.first]=p.second;
           // cout<<p.first.second<<"  "<<p.first.first<<"  "<<p.second<<endl;
            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&&ma[ny][nx]!='A'&&!visited[ny][nx]){
                    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++;
//        }
    }
}

C++: #include<iostream>
#include<queue>
#include<map>
#include<string>
#include<vector>
#include<algorithm>
#define all(c) c.begin(),c.end()
#define pb push_back
#define INF 10000000
using namespace std;
typedef pair<int,int> P;
int w,h;
vector<string> s;
P d[10];
int antime;
P q;
map<int,int> mp;
string op;
int dp[20][20];
bool in(P n){
	if(n.second>=0&&n.second<w&&n.first>=0&&n.first<h)
		return true;
	return false;
}
int ans;
int ret(P b,int time){
	//cout<<b.first<<"  "<<b.second<<endl;
	if(time>400)
	return INF;
	if(dp[b.first][b.second]<=time){
		q.first=b.first;
		q.second=b.second;
		return time;
	}
	P nb;
	nb.first=b.first+d[op[time%op.size()]-'0'].first;
	nb.second=b.second+d[op[time%op.size()]-'0'].second;
	if(!in(nb))
		nb=b;
	return ret(nb,time+1);
}
int dx[]={0,0,1,-1},dy[]={1,-1,0,0};
void bfs(P a){
	queue<P> que;
	que.push(a);
	dp[a.first][a.second]=0;
	while(!que.empty()){
		P t=que.front(),nt;
		que.pop();
		//cout<<dp[t.first][t.second]<<endl;
		for(int i=0;i<4;i++){
			nt.first=t.first+dy[i];
			nt.second=t.second+dx[i];
			if(in(nt)&&dp[nt.first][nt.second]==INF&&s[nt.first][nt.second]!='#'){
				que.push(nt);
				dp[nt.first][nt.second]=dp[t.first][t.second]+1;
			}
		}
	}
}
int main(){
	d[5]=P(0,0);d[8]=P(-1,0);d[6]=P(0,1);d[4]=P(0,-1);d[2]=P(1,0);
	mp[0]=5;mp[1]=8;mp[2]=6;mp[3]=4;mp[4]=2;
	while(cin>>h>>w,h||w){
		s.clear();
		P a,b;
		antime=INF;
		//memset(dp,-1,sizeof(dp));
		for(int i=0;i<h;i++)
		for(int j=0;j<w;j++)
		dp[i][j]=INF;
		for(int i=0;i<h;i++){
			string t;
			cin>>t;
			s.pb(t);
			for(int j=0;j<t.size();j++){
				if(t[j]=='A'){
					a.first=i;a.second=j;
				}else if(t[j]=='B'){
					b.first=i;b.second=j;
				}
			}
		}
		cin>>op;
		bfs(a);
		int ans=ret(b,0);
		if(ans!=INF)
			cout<<ans<<" "<<q.first<<" "<<q.second<<endl;
		else
			cout<<"impossible"<<endl;
	}
	return 0;
}