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

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;
	int cnt = 0;
	
	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);
			cnt++;
			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;
					int tt = 0; for(int j=0;j<H;j++) if(r[j]!=-1) tt += PopCnt(r[j]);
					if(tt <= Min)dfs(nMp,r,dep);
				}
			}else{
				var r = (int[])route.Clone();
				r[dep] = i;
				int tt = 0; for(int j=0;j<H;j++) if(r[j]!=-1) tt += PopCnt(r[j]);
				if(tt <= Min)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(){
		using( var r = new FastIn()){
			H = r.ReadInt();
			W = r.ReadInt();
			A = new int[H][];
			for(int i=0;i<H;i++) A[i] = new int[W];
			for(int i=0;i<H;i++){
				for(int j=0;j<W;j++){
					A[i][j] = r.ReadInt();
				}
			}
		}
	}

	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));}
}




class FastIn:IDisposable {
	int Size;
	byte[] Mem;
	int ptr;
	int rsize;
	bool unfinished;
	Stream stdin;
	void Init(int n) {
		Size = n;
		Mem = new byte[Size];
		rsize=(stdin=Console.OpenStandardInput()).Read(Mem, 0, Size);
		ptr = 0;
		unfinished=(rsize == Size);
	}
	void Next() {
		if (unfinished == false) return;
		rsize=stdin.Read(Mem, 0, Size);
		ptr = 0;
		unfinished = (rsize == Size);
	}
	
	~FastIn(){
		stdin.Dispose();
	}
	void IDisposable.Dispose(){
		stdin.Dispose();
	}
	public void Dispose(){
		stdin.Dispose();
	}
	
	public FastIn() {
		Init(100000);
	}
	public FastIn(int n) {
		Init(n);
	}
	public int ReadInt() {
		int ret = 0;
		int sig = 1;
		while (ptr < rsize && Mem[ptr] != ' ' && Mem[ptr] != '\n' && Mem[ptr] != '\r' ) {
			if(ret==0 && Mem[ptr] == '-'){
				sig *= -1; ptr++; continue;
			}
			ret = ret * 10 + Mem[ptr++] - '0';
			if (ptr == Size) Next();
		}
		while (ptr < rsize && (Mem[ptr] == ' ' || Mem[ptr] == '\n' || Mem[ptr] == '\r') ) {
			ptr++;
			if (ptr == Size) Next();
		}
		return ret*sig;
	}
	public uint ReadUint() {
		uint ret = 0;
		uint sig = 1;
		while (ptr < rsize && Mem[ptr] != ' ' && Mem[ptr] != '\n' && Mem[ptr] != '\r' ) {
			ret = ret * 10 + Mem[ptr++] - '0';
			if (ptr == Size) Next();
		}
		while (ptr < rsize && (Mem[ptr] == ' ' || Mem[ptr] == '\n' || Mem[ptr] == '\r') ) {
			ptr++;
			if (ptr == Size) Next();
		}
		return ret*sig;
	}
	public long ReadLong() {
		long ret = 0;
		long sig = 1;
		while (ptr < rsize && Mem[ptr] != ' ' && Mem[ptr] != '\n' && Mem[ptr] != '\r' ) {
			if(ret==0 && Mem[ptr] == '-'){
				sig *= -1; ptr++; continue;
			}
			ret = ret * 10 + Mem[ptr++] - '0';
			if (ptr == Size) Next();
		}
		while (ptr < rsize &&  (Mem[ptr] == ' ' || Mem[ptr] == '\n' || Mem[ptr] == '\r')  ) {
			ptr++;
			if (ptr == Size) Next();
		}
		return ret*sig;
	}
	
	public double ReadDouble() {
		double ret = 0;
		double sig = 1;
		bool dot = false;
		double keta = 0.1;
		while (ptr < rsize && Mem[ptr] != ' ' && Mem[ptr] != '\n' && Mem[ptr] != '\r' ) {
			if(ret==0 && Mem[ptr] == '-'){
				sig *= -1; ptr++;
				if (ptr == Size) Next();
				continue;
			}
			if(Mem[ptr] == '.'){
				dot = true;
				ptr++;
				if (ptr == Size) Next();
				continue;
			}
			if(!dot){
				ret = ret * 10 + Mem[ptr++] - '0';
				if (ptr == Size) Next();
			}else{
				ret = ret + (Mem[ptr++] - '0')*keta;
				keta /= 10.0;
				if (ptr == Size) Next();
			}
		}
		while (ptr < rsize && (Mem[ptr] == ' ' || Mem[ptr] == '\n' || Mem[ptr] == '\r') ) {
			ptr++;
			if (ptr == Size) Next();
		}
		return ret*sig;
	}

	public String ReadStr() {
		//2byte文字はNG
		StringBuilder sb = new StringBuilder();
		while (ptr < rsize && Mem[ptr] != ' ' && Mem[ptr] != '\n' && Mem[ptr] != '\r') {
			sb.Append((char)Mem[ptr++]);
			if (ptr == Size && unfinished) Next();
		}
		while (ptr < rsize &&  (Mem[ptr] == ' ' || Mem[ptr] == '\n' || Mem[ptr] == '\r') ) {
			ptr++;
			if (ptr == Size && unfinished) Next();
		}
		return sb.ToString();
	}
	public String ReadLine() {
		//極力使わない(split/parseするくらいなら上をつかう）
		StringBuilder sb = new StringBuilder();
		while (ptr < rsize && Mem[ptr] != '\n' && Mem[ptr] != '\r') {
			sb.Append((char)Mem[ptr++]);
			if (ptr == Size && unfinished) Next();
		}
		while (ptr < rsize &&  (Mem[ptr] == ' ' || Mem[ptr] == '\n' || Mem[ptr] == '\r')) {
			ptr++;
			if (ptr == Size && unfinished) Next();
		}
		return sb.ToString();
	}
}