#include<cstring>

#include<algorithm>

#include<iostream>

#include<cstdio>

#include<queue>

#define de system("pause");

using namespace std;

int r,c;

char s[][];

int aim[];

int ans=;

bool bz[][][];

bool check(int way,int x,int y)

{

    if(x<||x>r||y<||y>c)return ;

    if(way==)

    {

        if(s[x][y]=='#'||s[x][y+]=='#')return ;

        if(bz[x][y][])return ;

    }

    if(way==)

    {

        if(s[x][y]=='#'||s[x+][y]=='#')return ;

        if(bz[x][y][])return ;

    }

    if(way==)

    {

        if(s[x][y]=='#'||s[x][y]=='E')return ;

        if(bz[x][y][])return ;

    }

    return ;

}

struct node

{

    int way,x,y,step;

    node(int wa,int xx,int yy,int ste)

    {

        way=wa;

        x=xx;

        y=yy;

        step=ste;

    }

};

queue<node> q;

void so(int x,int y,int way,int step)

{

    bz[x][y][way]=;

    q.push(node(way,x,y,step));

    if(way==&&s[x][y]=='O')

    {

//        cout<<step<<endl;

        ans=min(ans,step);

    }

}

void bfs()

{

    while(!q.empty())

    {

        node now=q.front();

        int x=now.x,y=now.y,way=now.way,step=now.step;

        q.pop();

//        bz[x][y][way]=0;

        if(way==)

        {

            if(check(,x-,y)) so(x-,y,,step+);

            if(check(,x+,y)) so(x+,y,,step+);

            if(check(,x,y-)) so(x,y-,,step+);

            if(check(,x,y+)) so(x,y+,,step+);

        }

        if(way==)

        {

            if(check(,x-,y)) so(x-,y,,step+);

            if(check(,x+,y)) so(x+,y,,step+);

            if(check(,x,y-)) so(x,y-,,step+);

            if(check(,x,y+)) so(x,y+,,step+);

        }

        if(way==)

        {

            if(check(,x-,y)) so(x-,y,,step+);

            if(check(,x+,y)) so(x+,y,,step+);

            if(check(,x,y-)) so(x,y-,,step+);

            if(check(,x,y+)) so(x,y+,,step+);

        }

    }

}

int main()

{

    while()

    {

        while(q.size())q.pop();

        memset(bz,,sizeof bz);

        scanf("%d%d",&r,&c);

        if(r==&&c==)break;

        int a[][];

        int cnt=;

        ans=;

        for(int i=;i<=r;++i)

        {

            scanf("%s",s[i]+);

            for(int j=;j<=c;j++)

            {

                if(s[i][j]=='X')

                {

                    ++cnt;

                    a[cnt][]=i,a[cnt][]=j;

                }

            }

        }

        if(cnt==) q.push(node(,a[cnt][],a[cnt][],));

        else

        {

            if(a[][]==a[][]) q.push(node(,a[][],a[][],));

            else q.push(node(,a[][],a[][],));

        }

        bfs();

        if(ans==)puts("Impossible");

        else cout<<ans<<endl;

    }

    return ;

}