Buggy python submission (verdict: Time Limit Exceeded):
l = input().split()
H = int(l[0])
W = int(l[1])

S = []
for i in range(H):
    l = input().split()
    S.append(l[0])

# print(H, W, S)

# TS = []
# for i in range(W):
#     tmp = ''
#     for j in range(H):
#         tmp += S[j][i]
#     TS.append(tmp)

# print(TS)

HL = []
for i in range(H):
    l = 0
    begin = 0
    tmp = []
    for j in range(W):
        if S[i][j] == '.':
            l += 1
        else:
            tmp.extend([l]*(j - begin))
            tmp.append(0)
            begin = j + 1
            l = 0
    if begin != W:
        tmp.extend([l]*(W - begin))
    HL.append(tmp)

WL = []
for i in range(W):
    l = 0
    begin = 0
    tmp = []
    for j in range(H):
        if S[j][i] == '.':
            l += 1
        else:
            tmp.extend([l]*(j - begin))
            tmp.append(0)
            begin = j + 1
            l = 0
    if begin != H:
        tmp.extend([l]*(H - begin))
    WL.append(tmp)

max_l = 0
for i in range(H):
    for j in range(W):
        l = HL[i][j] + WL[j][i]
        max_l = max(l, max_l)
print(max_l - 1)


Fixed submission:
l = input().split()
H = int(l[0])
W = int(l[1])

S = []
for i in range(H):
    l = input().split()
    S.append(l[0])

# print(H, W, S)

# TS = []
# for i in range(W):
#     tmp = ''
#     for j in range(H):
#         tmp += S[j][i]
#     TS.append(tmp)

# print(TS)

HL = []
for i in range(H):
    l = 0
    begin = 0
    tmp = []
    for j in range(W):
        if S[i][j] == '.':
            l += 1
        else:
            tmp.extend([l]*(j - begin))
            tmp.append(0)
            begin = j + 1
            l = 0
    if begin != W:
        tmp.extend([l]*(W - begin))
    HL.append(tmp)

WL = []
for i in range(W):
    l = 0
    begin = 0
    tmp = []
    for j in range(H):
        if S[j][i] == '.':
            l += 1
        else:
            tmp.extend([l]*(j - begin))
            tmp.append(0)
            begin = j + 1
            l = 0
    if begin != H:
        tmp.extend([l]*(H - begin))
    WL.append(tmp)

max_l = 0
for i in range(H):
    for j in range(W):
        l = HL[i][j] + WL[j][i]
        max_l = max(l, max_l)
print(max_l - 1)

Buggy python submission (verdict: Runtime Error):
l = input().split()
H = int(l[0])
W = int(l[1])

S = []
for i in range(H):
    l = input().split()
    S.append(l[0])

# print(H, W, S)

# TS = []
# for i in range(W):
#     tmp = ''
#     for j in range(H):
#         tmp += S[j][i]
#     TS.append(tmp)

# print(TS)

HL = []
for i in range(H):
    l = 0
    begin = 0
    tmp = []
    for j in range(W):
        if S[i][j] == '.':
            l += 1
        else:
            tmp.extend([l]*(j - begin))
            tmp.append(0)
            begin = j + 1
            l = 0
    if begin != W:
        tmp.extend([l]*(W - begin))
    HL.append(tmp)

WL = []
for i in range(W):
    l = 0
    begin = 0
    tmp = []
    for j in range(H):
        if S[j][i] == '.':
            l += 1
        else:
            tmp.extend([l]*(j - begin))
            tmp.append(0)
            begin = j + 1
            l = 0
    if begin != W:
        tmp.extend([l]*(W - begin))
    WL.append(tmp)

max_l = 0
for i in range(H):
    for j in range(W):
        l = HL[i][j] + WL[j][i]
        max_l = max(l, max_l)
print(max_l - 1)


Fixed submission:
l = input().split()
H = int(l[0])
W = int(l[1])

S = []
for i in range(H):
    l = input().split()
    S.append(l[0])

# print(H, W, S)

# TS = []
# for i in range(W):
#     tmp = ''
#     for j in range(H):
#         tmp += S[j][i]
#     TS.append(tmp)

# print(TS)

HL = []
for i in range(H):
    l = 0
    begin = 0
    tmp = []
    for j in range(W):
        if S[i][j] == '.':
            l += 1
        else:
            tmp.extend([l]*(j - begin))
            tmp.append(0)
            begin = j + 1
            l = 0
    if begin != W:
        tmp.extend([l]*(W - begin))
    HL.append(tmp)

WL = []
for i in range(W):
    l = 0
    begin = 0
    tmp = []
    for j in range(H):
        if S[j][i] == '.':
            l += 1
        else:
            tmp.extend([l]*(j - begin))
            tmp.append(0)
            begin = j + 1
            l = 0
    if begin != H:
        tmp.extend([l]*(H - begin))
    WL.append(tmp)

max_l = 0
for i in range(H):
    for j in range(W):
        l = HL[i][j] + WL[j][i]
        max_l = max(l, max_l)
print(max_l - 1)

Buggy python submission (verdict: Runtime Error):
l = input().split()
H = int(l[0])
W = int(l[1])

S = []
for i in range(H):
    l = input().split()
    S.append(l[0])

# print(H, W, S)

TS = []
for i in range(W):
    tmp = ''
    for j in range(H):
        tmp += S[j][i]
    TS.append(tmp)

# print(TS)

HL = []
for i in range(H):
    l = 0
    begin = 0
    tmp = []
    for j in range(W):
        if S[i][j] == '.':
            l += 1
        else:
            tmp.extend([l]*(j - begin))
            tmp.append(0)
            begin = j + 1
            l = 0
    if begin != W:
        tmp.extend([l]*(W - begin))
    HL.append(tmp)

WL = []
for i in range(W):
    l = 0
    begin = 0
    tmp = []
    for j in range(H):
        if TS[i][j] == '.':
            l += 1
        else:
            tmp.extend([l]*(j - begin))
            tmp.append(0)
            begin = j + 1
            l = 0
    if begin != W:
        tmp.extend([l]*(W - begin))
    WL.append(tmp)

max_l = 0
for i in range(H):
    for j in range(W):
        l = HL[i][j] + WL[j][i]
        max_l = max(l, max_l)
print(max_l - 1)


Fixed submission:
l = input().split()
H = int(l[0])
W = int(l[1])

S = []
for i in range(H):
    l = input().split()
    S.append(l[0])

# print(H, W, S)

# TS = []
# for i in range(W):
#     tmp = ''
#     for j in range(H):
#         tmp += S[j][i]
#     TS.append(tmp)

# print(TS)

HL = []
for i in range(H):
    l = 0
    begin = 0
    tmp = []
    for j in range(W):
        if S[i][j] == '.':
            l += 1
        else:
            tmp.extend([l]*(j - begin))
            tmp.append(0)
            begin = j + 1
            l = 0
    if begin != W:
        tmp.extend([l]*(W - begin))
    HL.append(tmp)

WL = []
for i in range(W):
    l = 0
    begin = 0
    tmp = []
    for j in range(H):
        if S[j][i] == '.':
            l += 1
        else:
            tmp.extend([l]*(j - begin))
            tmp.append(0)
            begin = j + 1
            l = 0
    if begin != H:
        tmp.extend([l]*(H - begin))
    WL.append(tmp)

max_l = 0
for i in range(H):
    for j in range(W):
        l = HL[i][j] + WL[j][i]
        max_l = max(l, max_l)
print(max_l - 1)

Buggy python submission (verdict: Runtime Error):
l = input().split()
H = int(l[0])
W = int(l[0])

S = []
for i in range(H):
    l = input().split()
    S.append(l[0])

# print(H, W, S)

TS = []
for i in range(W):
    tmp = ''
    for j in range(H):
        tmp += S[j][i]
    TS.append(tmp)

# print(TS)

HL = []
for i in range(H):
    l = 0
    begin = 0
    tmp = []
    for j in range(W):
        if S[i][j] == '.':
            l += 1
        else:
            tmp.extend([l]*(j - begin))
            tmp.append(0)
            begin = j + 1
            l = 0
    if begin != W:
        tmp.extend([l]*(W - begin))
    HL.append(tmp)

WL = []
for i in range(W):
    l = 0
    begin = 0
    tmp = []
    for j in range(H):
        if TS[i][j] == '.':
            l += 1
        else:
            tmp.extend([l]*(j - begin))
            tmp.append(0)
            begin = j + 1
            l = 0
    if begin != W:
        tmp.extend([l]*(W - begin))
    WL.append(tmp)

# print(HL)
# print(WL)

max_l = 0
for i in range(H):
    for j in range(W):
        l = HL[i][j] + WL[j][i]
        if l > max_l:
            max_l = l
print(max_l - 1)


Fixed submission:
l = input().split()
H = int(l[0])
W = int(l[1])

S = []
for i in range(H):
    l = input().split()
    S.append(l[0])

# print(H, W, S)

# TS = []
# for i in range(W):
#     tmp = ''
#     for j in range(H):
#         tmp += S[j][i]
#     TS.append(tmp)

# print(TS)

HL = []
for i in range(H):
    l = 0
    begin = 0
    tmp = []
    for j in range(W):
        if S[i][j] == '.':
            l += 1
        else:
            tmp.extend([l]*(j - begin))
            tmp.append(0)
            begin = j + 1
            l = 0
    if begin != W:
        tmp.extend([l]*(W - begin))
    HL.append(tmp)

WL = []
for i in range(W):
    l = 0
    begin = 0
    tmp = []
    for j in range(H):
        if S[j][i] == '.':
            l += 1
        else:
            tmp.extend([l]*(j - begin))
            tmp.append(0)
            begin = j + 1
            l = 0
    if begin != H:
        tmp.extend([l]*(H - begin))
    WL.append(tmp)

max_l = 0
for i in range(H):
    for j in range(W):
        l = HL[i][j] + WL[j][i]
        max_l = max(l, max_l)
print(max_l - 1)