#include <iostream>
#include <queue>
#include <vector>
#include <cstring>

using namespace std;

struct Node {
    int x, y, time, killed;
    Node(int x, int y, int time, int killed) : x(x), y(y), time(time), killed(killed) {}
};

int dx[4] = {-1, 0, 1, 0};
int dy[4] = {0, 1, 0, -1};
char grid[21][21];
bool visited[21][21][2]; // visited[x][y][killed] 表示在(x, y)位置，是否杀过守卫的状态是否被访问过

int main() {
    int N, M;
    cin >> N >> M;
    for (int i = 1; i <= N; ++i) {
        for (int j = 1; j <= M; ++j) {
            cin >> grid[i][j];
        }
    }

    queue<Node> q;
    memset(visited, false, sizeof(visited));
    int sx, sy, ex, ey;
    bool foundStart = false, foundEnd = false;
    // 找到骑士和公主的位置
    for (int i = 1; i <= N; ++i) {
        for (int j = 1; j <= M; ++j) {
            if (grid[i][j] == 'r') {
                sx = i;
                sy = j;
                foundStart = true;
            } else if (grid[i][j] == 'a') {
                ex = i;
                ey = j;
                foundEnd = true;
            }
        }
    }

    if (!foundStart || !foundEnd) {
        cout << "Impossible" << endl;
        return 0;
    }

    q.push(Node(sx, sy, 0, 0));
    visited[sx][sy][0] = true;

    while (!q.empty()) {
        Node curr = q.front();
        q.pop();

        if (curr.x == ex && curr.y == ey) {
            cout << curr.time << endl;
            return 0;
        }

        for (int i = 0; i < 4; ++i) {
            int nx = curr.x + dx[i];
            int ny = curr.y + dy[i];
            if (nx < 1 || nx > N || ny < 1 || ny > M || grid[nx][ny] == '#') continue;
            if (grid[nx][ny] == 'x') {
                if (!visited[nx][ny][1]) {
                    q.push(Node(nx, ny, curr.time + 1 + 1, 1)); // 杀死守卫需要额外1个单位时间
                    visited[nx][ny][1] = true;
                }
            } else {
                int killed = curr.killed || (grid[nx][ny] == 'x');
                if (!visited[nx][ny][killed]) {
                    q.push(Node(nx, ny, curr.time + 1, killed));
                    visited[nx][ny][killed] = true;
                }
            }
        }
    }

    cout << "Impossible" << endl;
    return 0;
}
/**************************************************************
	Problem: 1901
	User: zhengzihao
	Language: C++
	Result: Accepted
	Time:13 ms
	Memory:2080 kb
****************************************************************/