#include <bits/stdc++.h>
using namespace std;
int n, m, zx, zy, nr, nc;
string a[1005];
int v[1005][1005];

int dr[] = {1, 0, -1, 0};
int dc[] = {0, 1, 0, -1};
const int bs[] = {1, 2, 4, 8, 16, 32, 64, 128, 256, 512};
void dfs(int r, int c) {
	a[r][c] = 'X';
	for (int i = 0; i < 10; i++) {
		for (int j = 0; j < 4; j++) {
			nr = r + i * dr[j];
			nc = c + i * dc[j];
			if (nr < 0 || nr > n - 1 ||
			        nc < 0 || nc > m - 1 ||
			        a[nr][nc] == 'X') {
				continue;
			}
			v[nr][nc] = v[r][c] + 1;
			//cout << nr << " " << nc << " " << v[nr][nc] << "\n";
			if (v[zx][zy] > 0) {
				return;
			}
			dfs(nr, nc);
		}
	}
}
int main() {
	cin.tie(0);
	cin >> n >> m;
	for (int i = 0; i < n; i++) {
		cin >> a[i];
	}
	/*for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			cout << a[i][j] << " ";
		}
		cout << "\n";
	}*/
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= m; j++) {
			if (a[i][j] == '#') {
				zx = i;
				zy = j;
				//cout << zx << " " << zy << "\n";
			}
		}
	}
	dfs(0, 0);
	if (v[zx][zy] > 0) {
		cout << v[zx][zy];
	} else {
		cout << -1;
	}
	return 0;
}

样例过了，但提交只对了一个......

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