H, W = map(int, input().split())
S = [input() for _ in range(H)]

ans = []

# 横
for i in range(H):
    for j in range(W):
        if S[i][j] == '.':
            if j == 0 or S[i][j-1] == '#':
                if j+1 < W and S[i][j+1] == '.':
                    k = j
                    while k < W and S[i][k] == '.':
                        k += 1
                    ans.append('a' * (k-j))

# 縦
for i in range(H):
    for j in range(W):
        if S[i][j] == '.':
            if i == 0 or S[i-1][j] == '#':
                if i+1 < H and S[i+1][j] == '.':
                    k = i
                    while k < H and S[k][j] == '.':
                        k += 1
                    ans.append('a' * (k-i))

ans.sort(key=lambda x: x[0])
print('\n'.join(x[1] for x in ans))