def flip(b, x, y):
    for i in range(-1, 2):
        for j in range(-1, 2):
            if 0<=x-i<M and 0<=y-j<N:
                b[x-i][y-j] = 1^b[x-i][y-j]
    
    return b
    
M, N = map(int, input().split())
a = [list(map(int, input().split())) for _ in range(M)]
ans = 10**18

for i in range(2**N):
    for j in range(2**M):
        b = [[0]*N for _ in range(M)]
        
        for k in range(M):
            for l in range(N):
                b[k][l] = a[k][l]
        
        ans_cand = 0
        
        for k in range(N):
            if (i>>k)&1:
                ans_cand += 1
                b = flip(b, 0, k)
            
        for k in range(M):
            if (j>>k)&1:
                ans_cand += 1
                b = flip(b, k, 0)
        
        for k in range(1, M):
            for l in range(1, N):
                if b[k-1][l-1]==1:
                    ans_cand += 1
                    b = flip(b, k, l)

        for k in range(M):
            for l in range(N):
                if b[k][l]==1:
                    break
            else:
                continue
            break
        else:
            ans = min(ans, ans_cand)
            
if ans==10**18:
    print('Impossible')
else:
    print(ans)