Buggy python submission (verdict: Time Limit Exceeded):
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

import heapq

def main():
    H, W, M = map(int, readline().split())
    m = map(int,read().split())
    hw = list(zip(m,m))

    row_bombers = [0] * (H+1)
    col_bombers = [0] * (W+1)

    for (h, w) in hw:
        row_bombers[h] += 1
        col_bombers[w] += 1

    row_max = max(row_bombers)
    col_max = max(col_bombers)

    max_rows = [i for i in range(H+1) if row_bombers[i] == row_max]
    max_cols = [i for i in range(W+1) if col_bombers[i] == col_max]

    ans = row_max + col_max
    
    num_empty_cells_in_kouho = len(max_rows) * len(max_cols)
    for (h, w) in hw:
        if h in max_rows and w in max_cols:
            num_empty_cells_in_kouho -= 1

    if num_empty_cells_in_kouho == 0:
        ans -= 1
    
    print(ans)


if __name__ == '__main__':
    main()

Fixed submission:
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

import heapq

def main():
    H, W, M = map(int, readline().split())
    m = map(int,read().split())
    hw = list(zip(m,m))

    row_bombers = [0] * (H+1)
    col_bombers = [0] * (W+1)

    for (h, w) in hw:
        row_bombers[h] += 1
        col_bombers[w] += 1

    row_max = max(row_bombers)
    col_max = max(col_bombers)

    max_rows = [i for i in range(H+1) if row_bombers[i] == row_max]
    max_cols = [i for i in range(W+1) if col_bombers[i] == col_max]

    ans = row_max + col_max
    
    num_empty_cells_in_kouho = len(max_rows) * len(max_cols)
    for (h, w) in hw:
        if row_bombers[h] == row_max and col_bombers[w] == col_max:
            num_empty_cells_in_kouho -= 1

    if num_empty_cells_in_kouho == 0:
        ans -= 1
    
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

import heapq

def main():
    H, W, M = map(int, readline().split())
    m = map(int,read().split())
    hw = list(zip(m,m))

    row_bombers = [0] * (H+1)
    col_bombers = [0] * (W+1)

    for (h, w) in hw:
        row_bombers[h] += 1
        col_bombers[w] += 1

    row_max = max(row_bombers)
    col_max = max(col_bombers)

    max_rows = [i for i in range(H+1) if row_bombers[i] == row_max]
    max_cols = [i for i in range(W+1) if col_bombers[i] == col_max]

    ans = row_max + col_max
    
    num_empty_cells_in_kouho = len(max_rows) * len(max_cols)
    for (h, w) in hw:
        if h in max_rows and w in max_cols:
            num_empty_cells_in_kouho -= 1

    if num_empty_cells_in_kouho == 0:
        ans -= 1
    
    print(ans)


if __name__ == '__main__':
    main()

Fixed submission:
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

import heapq

def main():
    H, W, M = map(int, readline().split())
    m = map(int,read().split())
    hw = list(zip(m,m))

    row_bombers = [0] * (H+1)
    col_bombers = [0] * (W+1)

    for (h, w) in hw:
        row_bombers[h] += 1
        col_bombers[w] += 1

    row_max = max(row_bombers)
    col_max = max(col_bombers)

    max_rows = [i for i in range(H+1) if row_bombers[i] == row_max]
    max_cols = [i for i in range(W+1) if col_bombers[i] == col_max]

    ans = row_max + col_max
    
    num_empty_cells_in_kouho = len(max_rows) * len(max_cols)
    for (h, w) in hw:
        if row_bombers[h] == row_max and col_bombers[w] == col_max:
            num_empty_cells_in_kouho -= 1

    if num_empty_cells_in_kouho == 0:
        ans -= 1
    
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

import heapq

def main():
    H, W, M = map(int, readline().split())
    m = map(int,read().split())
    hw = list(zip(m,m))

    bR = [0] * (H+1)
    bC = [0] * (W+1)

    maxes = []
    x = [[False] * (W+1) for i in range(H+1)]

    for (h, w) in hw:
        bR[h] += 1
        bC[w] += 1
        x[h][w] = True

    rmax = max(bR)
    cmax = max(bC)
    rmis = [i for i in range(H+1) if bR[i] == rmax]
    cmis = [i for i in range(W+1) if bC[i] == cmax]

    ans = rmax + cmax
    minus_flag = True
    for r in rmis:
        for c in cmis:
            if not x[r][c]:
                minus_flag = False
                break
    if minus_flag:
        ans -= 1

    
    # print(hw)
    # print(bR, bC)
    # print(rmax, cmax, rmis, cmis)
    print(ans)


if __name__ == '__main__':
    main()

Fixed submission:
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

import heapq

def main():
    H, W, M = map(int, readline().split())
    m = map(int,read().split())
    hw = list(zip(m,m))

    row_bombers = [0] * (H+1)
    col_bombers = [0] * (W+1)

    for (h, w) in hw:
        row_bombers[h] += 1
        col_bombers[w] += 1

    row_max = max(row_bombers)
    col_max = max(col_bombers)

    max_rows = [i for i in range(H+1) if row_bombers[i] == row_max]
    max_cols = [i for i in range(W+1) if col_bombers[i] == col_max]

    ans = row_max + col_max
    
    num_empty_cells_in_kouho = len(max_rows) * len(max_cols)
    for (h, w) in hw:
        if row_bombers[h] == row_max and col_bombers[w] == col_max:
            num_empty_cells_in_kouho -= 1

    if num_empty_cells_in_kouho == 0:
        ans -= 1
    
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

import heapq

def main():
    H, W, M = map(int, readline().split())
    m = map(int,read().split())
    hw = list(zip(m,m))

    bR = [0] * (H+1)
    bC = [0] * (W+1)

    maxes = []
    heapq.heapify([])

    for (h, w) in hw:
        bR[h] += 1
        bC[w] += 1

    rmax = max(bR)
    cmax = max(bC)
    rmis = [i for i in range(H+1) if bR[i] == rmax]
    cmis = [i for i in range(W+1) if bC[i] == cmax]

    ans = rmax + cmax
    minus_flag = True
    for r in rmis:
        for c in cmis:
            if (r, c) not in hw:
                minus_flag = False
                break
    if minus_flag:
        ans -= 1

    
    # print(hw)
    # print(bR, bC)
    # print(rmax, cmax, rmis, cmis)
    print(ans)


if __name__ == '__main__':
    main()

Fixed submission:
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

import heapq

def main():
    H, W, M = map(int, readline().split())
    m = map(int,read().split())
    hw = list(zip(m,m))

    row_bombers = [0] * (H+1)
    col_bombers = [0] * (W+1)

    for (h, w) in hw:
        row_bombers[h] += 1
        col_bombers[w] += 1

    row_max = max(row_bombers)
    col_max = max(col_bombers)

    max_rows = [i for i in range(H+1) if row_bombers[i] == row_max]
    max_cols = [i for i in range(W+1) if col_bombers[i] == col_max]

    ans = row_max + col_max
    
    num_empty_cells_in_kouho = len(max_rows) * len(max_cols)
    for (h, w) in hw:
        if row_bombers[h] == row_max and col_bombers[w] == col_max:
            num_empty_cells_in_kouho -= 1

    if num_empty_cells_in_kouho == 0:
        ans -= 1
    
    print(ans)


if __name__ == '__main__':
    main()