#include <cstdio>
#include <cmath>

typedef long long   signed int LL;
typedef long long unsigned int LU;

#define incID(i, l, r) for(int i = (l)    ; i <  (r); i++)
#define incII(i, l, r) for(int i = (l)    ; i <= (r); i++)
#define decID(i, l, r) for(int i = (r) - 1; i >= (l); i--)
#define decII(i, l, r) for(int i = (r)    ; i >= (l); i--)
#define inc( i, n) incID(i, 0, n)
#define inc1(i, n) incII(i, 1, n)
#define dec( i, n) decID(i, 0, n)
#define dec1(i, n) decII(i, 1, n)

#define inII(v, l, r) ((l) <= (v) && (v) <= (r))
#define inID(v, l, r) ((l) <= (v) && (v) <  (r))

template<typename T> void swap(T & x, T & y) { T t = x; x = y; y = t; return; }
template<typename T> T abs(T x) { return (0 <= x ? x : -x); }
template<typename T> T max(T a, T b) { return (b <= a ? a : b); }
template<typename T> T min(T a, T b) { return (a <= b ? a : b); }
template<typename T> bool setmin(T & a, T b) { if(a <= b) { return false; } else { a = b; return true; } }
template<typename T> bool setmax(T & a, T b) { if(b <= a) { return false; } else { a = b; return true; } }
template<typename T> T gcd(T a, T b) { return (b == 0 ? a : gcd(b, a % b)); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }

// ---- ----

int m, n, a[8][8];

int b[8][8];
void flip(int i, int j) {
	incII(ii, -1, 1) {
	incII(jj, -1, 1) {
		if(inID(i + ii, 0, m) && inID(j + jj, 0, n)) {
			b[i + ii][j + jj] ^= 1;
		}
	}
	}
}

int main() {
	scanf("%d%d", &m, &n);
	inc(i, m) {
	inc(j, n) {
		scanf("%d", &a[i][j]);
	}
	}
	
	int mi = 65;
	inc(bit, 1 << (n + m - 1)) {
		int c = 0;
		
		inc(i, m) {
		inc(j, n) {
			b[i][j] = a[i][j];
		}
		}
		inc(k, n + m - 1) {
			if(bit & (1 << k)) { } else { continue; }
			int i, j;
			if(k < n) { i = 0; j = k; } else { i = k - (n - 1); j = 0; }
			flip(i, j);
			c++;
		}
		incID(i, 1, m) {
		incID(j, 1, n) {
			if(b[i - 1][j - 1]) {
				flip(i, j);
				c++;
			}
		}
		}
		
		bool flag = true;
		inc(i, m) {
		inc(j, n) {
			if(b[i][j]) { flag = false; break; }
		}
		}
		
		if(flag) { setmin(mi, c); }
	}
	
	if(mi == 65) { printf("Impossible"); } else { printf("%d\n", mi); }
	
	return 0;
}