h, w = map(int, input().split()); assert 2 <= min(h, w) and max(h, w) <= 2000
A = [list(map(int, input().split())) for _ in range(h)]
for y in range(h): assert 0 <= min(A[y]) and max(A[y]) <= 1
Y = [0] * h
X = [0] * w
for y in range(h):
    for x in range(w):
        Y[y] ^= A[y][x]
        X[x] ^= A[y][x]

print(max(sum(Y), sum(X)))