H, W = map(int, input().split())

S = []

for i in range(H):
    for j, a in enumerate(list(map(int, input().split()))):
        if a > 0:
            S.append((a, i, j))
            
S.sort(reverse=True)

cnt = 0
while len(S) > 0:
    a, i, j = S.pop(0)
    ai = []
    aj = []
    for b in S:
        if b[0] != a:
            break
        if i == b[1]:
            ai.append(b)
        elif j == b[2]:
            aj.append(b)
    for b in ai if len(ai) >= len(aj) else aj:
        S.remove(b)
    cnt += 1

print(cnt)