import sys

def solve():
    input_data = sys.stdin.read().split()
    if not input_data:
        return
    
    H = int(input_data[0])
    W = int(input_data[1])
    grid = input_data[2:]
    
    R = 2 * H - 1
    C = 2 * W - 1
    N = R * C
    
    # bytearray super cepat & hemat memori untuk Python
    visited = bytearray(N)
    
    # Pre-fill grid walls
    for r in range(H):
        row = grid[r]
        base = 2 * r * C
        for c in range(W):
            if row[c] == '#':
                visited[base + 2 * c] = 1
                
    target = N - 1
    if target == 0:
        print(0)
        return
        
    q = [0]
    visited[0] = 1
    step = 0
    
    C2 = 2 * C
    
    while q:
        step += 1
        new_q = []
        app = new_q.append
        
        for u in q:
            c = u % C
            r = u // C
            
            # 1-step moves (semua cell bisa geser pelan)
            if c > 0:
                nxt = u - 1
                if not visited[nxt]:
                    visited[nxt] = 1
                    app(nxt)
            if c < C - 1:
                nxt = u + 1
                if not visited[nxt]:
                    visited[nxt] = 1
                    app(nxt)
            if r > 0:
                nxt = u - C
                if not visited[nxt]:
                    visited[nxt] = 1
                    app(nxt)
            if r < R - 1:
                nxt = u + C
                if not visited[nxt]:
                    visited[nxt] = 1
                    app(nxt)
                    
            # 2-step jump horizontal (hanya untuk cell asli & lorong horizontal)
            if (c & 1) == 0:
                if c >= 2:
                    nxt = u - 2
                    if not visited[nxt]:
                        visited[nxt] = 1
                        app(nxt)
                if c < C - 2:
                    nxt = u + 2
                    if not visited[nxt]:
                        visited[nxt] = 1
                        app(nxt)
                        
            # 2-step jump vertical (hanya untuk cell asli & lorong vertikal)
            if (r & 1) == 0:
                if r >= 2:
                    nxt = u - C2
                    if not visited[nxt]:
                        visited[nxt] = 1
                        app(nxt)
                if r < R - 2:
                    nxt = u + C2
                    if not visited[nxt]:
                        visited[nxt] = 1
                        app(nxt)
                        
        if visited[target]:
            print(step)
            return
            
        q = new_q
        
    print(-1)

if __name__ == '__main__':
    solve()