using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;

class TEST{
	static void Main(){
		Sol mySol =new Sol();
		mySol.Solve();
	}
}

class Sol{
	public void Solve(){
		int[] a0 = new int[H];
		for(int i=0;i<H;i++){
			for(int j=0;j<W;j++){
				if(A[i][j] == 1){
					a0[i] |= (1<<j);
				}
			}
		}
		
		Min = 9999;
		fm = (1<<W)-1;
		int[] r = Enumerable.Repeat(-1,H).ToArray();
		dfs(a0,r,-1);
		
		Console.WriteLine(Min == 9999 ? "Impossible" : Min.ToString());
		
	}
	
	int Min;
	int fm;
	
	void dfs(int[] Mp, int[] route, int dep){
		if(dep == H-1){
			for(int i=0;i<H;i++) if(Mp[i] != 0) return;
			int tot = 0;
			for(int i=0;i<H;i++) tot += PopCnt(route[i]);
			Min = Math.Min(Min,tot);
			return;
		}
		
		dep++;
		for(int i=0;i<(1<<W);i++){
			int lm = 0;
			for(int j=0;j<W;j++){
				if(((i>>j) & 1) == 1){
					lm ^= j == 0 ? 3 : (7<<(j-1));
				}
			}
			lm &= fm;
			
			int[] nMp = (int[]) Mp.Clone();
			for(int j=dep-1;j<=dep+1;j++){
				if(j<0 || j>=H)continue;
				nMp[j] ^= lm;
			}
			
			if(dep-1>=0){
				if(nMp[dep-1] == 0){
					var r = (int[])route.Clone();
					r[dep] = i;
					dfs(nMp,r,dep);
				}
			}else{
				var r = (int[])route.Clone();
				r[dep] = i;
				dfs(nMp,r,dep);
			}
		}
	}
	
	
	int PopCnt(int bits){
		bits = (bits & 0x55555555) + (bits >> 1 & 0x55555555);
		bits = (bits & 0x33333333) + (bits >> 2 & 0x33333333);
		bits = (bits & 0x0f0f0f0f) + (bits >> 4 & 0x0f0f0f0f);
		bits = (bits & 0x00ff00ff) + (bits >> 8 & 0x00ff00ff);
		return (bits & 0x0000ffff) + (bits >>16 & 0x0000ffff);
	}
	
	int H,W;
	int[][] A;
	public Sol(){
		var d = ria();
		H = d[0]; W = d[1];
		
		A = new int[H][];
		for(int i=0;i<H;i++)A[i] = ria();
	}

	static String rs(){return Console.ReadLine();}
	static int ri(){return int.Parse(Console.ReadLine());}
	static long rl(){return long.Parse(Console.ReadLine());}
	static double rd(){return double.Parse(Console.ReadLine());}
	static String[] rsa(char sep=' '){return Console.ReadLine().Split(sep);}
	static int[] ria(char sep=' '){return Array.ConvertAll(Console.ReadLine().Split(sep),e=>int.Parse(e));}
	static long[] rla(char sep=' '){return Array.ConvertAll(Console.ReadLine().Split(sep),e=>long.Parse(e));}
	static double[] rda(char sep=' '){return Array.ConvertAll(Console.ReadLine().Split(sep),e=>double.Parse(e));}
}