#include<iostream>
#include<vector>
#include<string>
#include<algorithm>	
#include<map>
#include<set>
#include<utility>
#include<cmath>
#include<cstring>
#include<queue>
#include<cstdio>
#include<sstream>
#include<iomanip>
#define loop(i,a,b) for(int i=a;i<b;i++) 
#define rep(i,a) loop(i,0,a)
#define pb push_back
#define mp make_pair
#define all(in) in.begin(),in.end()
#define shosu(x) fixed<<setprecision(x)
using namespace std;
//kaewasuretyuui
typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<pii> vp;
typedef vector<vp> vvp;
typedef pair<int,pii> pip;
typedef vector<pip>vip	;
const double PI=acos(-1);
const double EPS=1e-8;
const int inf=1<<30;
int dx[]={0,0,1,-1};
int dy[]={1,-1,0,0};
int dp[110][110];
int main(){
	int n,m;
	while(cin>>m>>n,n+m){
		vector<string>in(n);
		rep(i,n)cin>>in[i];
		queue<pip>q;
		int sx,sy;
		rep(i,110)rep(j,110)dp[i][j]=inf;
		rep(i,n)rep(j,m)if(i==0||j==0||i==n-1||j==m-1){
			if(in[i][j]!='#'){
				q.push(pip(i,pii(j,0)));
				dp[i][j]=0;
			}else{
				q.push(pip(i,pii(j,1)));
				dp[i][j]=1;
			}
		}
		rep(i,n)rep(j,m)if(in[i][j]=='&')sx=i,sy=j;
		while(!q.empty()){
			pip p=q.front();
			q.pop();
			int x=p.first,y=p.second.first,cost=p.second.second;
//			cout<<x<<" "<<y<<" "<<cost<<endl;
			if(dp[x][y]<cost)continue;
			rep(k,4){
				int nx=x+dx[k],ny=y+dy[k];
				if(nx<0||ny<0||nx>=n||ny>=m)continue;
				int ncost=cost+(in[nx][ny]=='#'?1:0);
				if(in[nx][ny]=='#'&&in[x][y]=='#')ncost--;
//				cout<<" "<<nx<<" "<<ny<<" "<<ncost<<endl;
				if(dp[nx][ny]>ncost){
					dp[nx][ny]=ncost;
					q.push(pip(nx,pii(ny,ncost)));					
				}
			}
		}
		cout<<dp[sx][sy]<<endl;
	}
}