import sys
read=sys.stdin.buffer.read
readline=sys.stdin.buffer.readline
readlines=sys.stdin.buffer.readlines

n, m=map(int, readline().split())
a=list(map(int, read().split()))
x=0
for i, k in enumerate(a):
    if k:
        x^=(1<<i)
def Gauss_Jordan(v):
    basis=[]
    idx=[]
    idxb=[]
    w=[0]*(len(v))
    for i, x in enumerate(v):
        y=x
        for b, j in basis:
            if (y^b)<y:
                y^=b
                w[i]^=w[j]
        if y:
            w[i]^=(1<<i)
            basis.append((y, i))
        else:
            idx.append(i)
    return (basis, idx, w)
v=[0]*(n*m)
for i in range(n):
    for j in range(m):
        for dx in range(-1, 2):
            for dy in range(-1, 2):
                i1, j1=i+dx, j+dy
                if i1<0 or i1>=n or j1<0 or j1>=m:
                    continue
                v[i*m+j]^=(1<<(i1*m+j1))
basis, idx, w=Gauss_Jordan(v)
z=x
for b, i in basis:
    if (z^b)<z:
        z^=b
if z:
    print("Impossible")
    exit()
k=len(idx)
ans=n*m
for i in range(1<<k):
    x1=x
    cnt=0
    for j in range(k):
        if i&(1<<j):
            x1^=v[idx[j]]
            cnt+=1
    if x1==0:
        ans=min(ans, cnt)
        continue
    z=0
    for b, j in basis:
        if (x1^b)<x1:
            z^=w[j]
            x1^=b
    cnt+=bin(z).count('1')
    ans=min(ans, cnt)
print(ans)