Buggy python submission (verdict: Runtime Error):
import sys
input=sys.stdin.readline
H, W = map(int, input().split())
d = []
d2 = []
d3 = []
for h in range(H):
    s = input().strip() + "#"
    d.append(s)
    d2.append(sc(s))

for i in range(W):
    s = ""
    for j in range(H):
        s += d[j][i]
    s += "#"
    d3.append(sc(s))

Fixed submission:
H, W = map(int, input().split())
import sys
input = sys.stdin.readline
def sc(s):
    b = None
    nc = 0
    kk = [0]*len(s)
    for i, c in enumerate(s):
        if c == ".":
            if c == b:
                nc += 1
            else:
                si = i
        else:
            if b == ".":
                for j in range(si, i):
                    kk[j] = i - si
            nc = 0
        b = c
    return kk
d = []
d2 = []
d3 = []
for h in range(H):
    s = input().strip()
    d.append(s)
    d2.append(sc(s+"#"))

d = list(zip(*d))
for s in d:
    d3.append(sc("".join(s)+"#"))
r = 0
for i in range(H):
    for j in range(W):
        r = max(r, d2[i][j] + d3[j][i]-1)
print(r)

Buggy python submission (verdict: Runtime Error):
H, W = map(int, input().split())
import sys
input = sys.stdin.readline
def sc(s):
    b = None
    nc = 0
    kk = [0]*len(s)
    for i, c in enumerate(s):
        if c == ".":
            if c == b:
                nc += 1
            else:
                si = i
        else:
            if b == ".":
                for j in range(si, i):
                    kk[j] = i - si
            nc = 0
        b = c
    return kk
d = []
d2 = []
d3 = [[0]*W for _ in range(H)]
for h in range(H):
    s = input().strip() + "#"
    d.append(s)
    d2.append(sc(s))

r = 0
for i in range(H):
    for j in range(W):
        r = max(r, d2[i][j] + d3[j][i]-1)
print(r)


Fixed submission:
H, W = map(int, input().split())
import sys
input = sys.stdin.readline
def sc(s):
    b = None
    nc = 0
    kk = [0]*len(s)
    for i, c in enumerate(s):
        if c == ".":
            if c == b:
                nc += 1
            else:
                si = i
        else:
            if b == ".":
                for j in range(si, i):
                    kk[j] = i - si
            nc = 0
        b = c
    return kk
d = []
d2 = []
d3 = []
for h in range(H):
    s = input().strip()
    d.append(s)
    d2.append(sc(s+"#"))

d = list(zip(*d))
for s in d:
    d3.append(sc("".join(s)+"#"))
r = 0
for i in range(H):
    for j in range(W):
        r = max(r, d2[i][j] + d3[j][i]-1)
print(r)

Buggy python submission (verdict: Time Limit Exceeded):
H, W = map(int, input().split())
import sys
input = sys.stdin.readline
def sc(s):
    b = None
    nc = 0
    kk = [0]*len(s)
    for i, c in enumerate(s):
        if c == ".":
            if c == b:
                nc += 1
            else:
                si = i
        else:
            if b == ".":
                for j in range(si, i):
                    kk[j] = i - si
            nc = 0
        b = c
    return kk
d = []
d2 = []
d3 = []
for h in range(H):
    s = input().strip() + "#"
    d.append(s)
    d2.append(sc(s))

for i in range(W):
    s = ""
    for j in range(H):
        s += d[j][i]
    s += "#"
    d3.append(sc(s))
r = 0
for i in range(H):
    for j in range(W):
        r = max(r, d2[i][j] + d3[j][i]-1)
print(r)


Fixed submission:
H, W = map(int, input().split())
import sys
input = sys.stdin.readline
def sc(s):
    b = None
    nc = 0
    kk = [0]*len(s)
    for i, c in enumerate(s):
        if c == ".":
            if c == b:
                nc += 1
            else:
                si = i
        else:
            if b == ".":
                for j in range(si, i):
                    kk[j] = i - si
            nc = 0
        b = c
    return kk
d = []
d2 = []
d3 = []
for h in range(H):
    s = input().strip()
    d.append(s)
    d2.append(sc(s+"#"))

d = list(zip(*d))
for s in d:
    d3.append(sc("".join(s)+"#"))
r = 0
for i in range(H):
    for j in range(W):
        r = max(r, d2[i][j] + d3[j][i]-1)
print(r)

Buggy python submission (verdict: Time Limit Exceeded):
H, W = map(int, input().split())
def sc(s):
    b = None
    nc = 0
    kk = []
    for i, c in enumerate(s):
        if c == ".":
            if c == b:
                nc += 1
            else:
                si = i
        else:
            if b == ".":
                ei = i
                kk.append((si, ei))
        b = c
    return kk
d = []
d2 = [[0] * W for _ in range(H)]
d3 = [[0] * W for _ in range(H)]
for h in range(H):
    s = input().strip() + "#"
    d.append(s)
    r = sc(s)
    for ss, tt in r:
        for i in range(ss, tt):
            d2[h][i] = tt - ss
for i in range(W):
    s = ""
    for j in range(H):
        s += d[j][i]
    s += "#"
    r = sc(s)
    for ss, tt in r:
        for k in range(ss, tt):
            d3[k][i] = tt - ss
r = 0
for i in range(H):
    for j in range(W):
        r = max(r, d2[i][j] + d3[i][j]-1)
print(r)


Fixed submission:
H, W = map(int, input().split())
import sys
input = sys.stdin.readline
def sc(s):
    b = None
    nc = 0
    kk = [0]*len(s)
    for i, c in enumerate(s):
        if c == ".":
            if c == b:
                nc += 1
            else:
                si = i
        else:
            if b == ".":
                for j in range(si, i):
                    kk[j] = i - si
            nc = 0
        b = c
    return kk
d = []
d2 = []
d3 = []
for h in range(H):
    s = input().strip()
    d.append(s)
    d2.append(sc(s+"#"))

d = list(zip(*d))
for s in d:
    d3.append(sc("".join(s)+"#"))
r = 0
for i in range(H):
    for j in range(W):
        r = max(r, d2[i][j] + d3[j][i]-1)
print(r)