#include<bits/stdc++.h>

#define REP(i,s,n) for(int i=s;i<n;i++)
#define rep(i,n) REP(i,0,n)

using namespace std;

const int IINF = INT_MAX;
const int MAX_W = 9;
typedef pair<int,int> ii;


int h,w;
int field[10][10],indice[10][10];
int dp[2][1<<((MAX_W+1)*2)];
int dx[] = {1,0,-1,0};
int dy[] = {0,1,0,-1};

inline bool isValid(int x,int y) { return 0 <= x && x < w && 0 <= y && y < h; }

#define SET(bitmask,index,value) ( bitmask = ( ( bitmask & ~(1<<(2*index)) & ~(1<<(2*index+1)) ) | ( value << (index*2) ) ) )
#define GET(bitmask,x) ( ( ( bitmask >> ( 2 * x ) ) & 1 ) | ( ( ( bitmask >> (2*x+1) ) & 1) << 1 ) )
#define FIX(bitmask) ((bitmask<<2)&((1<<(2*(w+1)))-1))
#define STAR ( field[y][x] == 2 || field[y][x] == 3 )
#define update(x,v) ( ( x == -1 ) ? ( x = v ) : ( x = min(x,v) ) )


void compute(){

  vector<int> state;
  rep(bitmask,(1<<((w+1)*2))) {
    bool success = true;
    for(int i=0;i<(w+1)*2;i+=2) if( ( ( bitmask >> i ) & 1 ) && ( ( bitmask >> (i+1) ) & 1 ) ) { success = false; break; }
    if( success ) state.push_back(bitmask);
  }
  memset(dp,-1,sizeof(dp));

  int _size = state.size();
  bool initter = true, phase = false;
  int mini = IINF;
  int encounter = 0;
  rep(y,h){
    rep(x,w){

      if( field[y][x] == 2 || field[y][x] == 3 ) ++encounter;
      if( initter ) dp[phase][0] = 0;

      rep(i,_size){
        int bitmask = state[i];

        if( dp[phase][bitmask] == -1 ) continue;

        // ?????????
        if( field[y][x] == 1 ) {
          int nbitmask = bitmask;
          SET(nbitmask,x,0);
          if( x == w-1 ) nbitmask = FIX(nbitmask);
          update(dp[!phase][nbitmask],dp[phase][bitmask]);
          continue;
        }

        int nbitmask;
        // 0 0
        if( !( ( GET(bitmask,x) == 0 ) && ( GET(bitmask,(x+1)) == 0 ) ) ) goto Label1;
        if( STAR ) {
          // x 0
          if( y+1 < h && field[y+1][x] != 1 ) {
            nbitmask = bitmask;
            SET(nbitmask,x,((field[y][x]==3)+1));
            if( x == w-1 ) nbitmask = FIX(nbitmask);
          
            update(dp[!phase][nbitmask],dp[phase][bitmask]+1);
          }
          // 0 x
          if( x+1 < w && field[y][x+1] != 1 ) {
            nbitmask = bitmask;
            SET(nbitmask,(x+1),((field[y][x]==3)+1));

            if( x == w-1 ) nbitmask = FIX(nbitmask);

            update(dp[!phase][nbitmask],dp[phase][bitmask]+1);
          }
        } else {
          // x x
          if( x+1 < w && y+1 < h && field[y][x+1] != 1 && field[y+1][x] != 1 ) {
            REP(color,1,3){
              nbitmask = bitmask;
              SET(nbitmask,x,color);
              SET(nbitmask,(x+1),color);
              if( x == w-1 ) nbitmask = FIX(nbitmask);
              update(dp[!phase][nbitmask],(dp[phase][bitmask]+1));
            }
          }
          // 0 0
          nbitmask = bitmask;
          SET(nbitmask,x,0);
          SET(nbitmask,(x+1),0);
          if( x == w-1 ) nbitmask = FIX(nbitmask);
          update(dp[!phase][nbitmask],dp[phase][bitmask]);
        }

        continue;
      Label1:;
        // x 0
        // 0 x
        int color;
        if( !( ( GET(bitmask,x) && ( GET(bitmask,(x+1)) == 0 ) ) || ( GET(bitmask,(x+1)) && ( GET(bitmask,x) == 0 ) ) ) ) goto Label2;
        color = GET(bitmask,x) | GET(bitmask,(x+1));
        if( STAR ) {
          // 0 0
          if( ((color==1)?2:3) == field[y][x] ) {
            nbitmask = bitmask;
            SET(nbitmask,x,0);
            SET(nbitmask,(x+1),0);
            if( x == w-1 ) nbitmask = FIX(nbitmask);
            update(dp[!phase][nbitmask],dp[phase][bitmask]+1);
          }
        } else {
          // x 0
          if( y+1 < h && field[y+1][x] != 1 ) {
            nbitmask = bitmask;
            SET(nbitmask,x,color);
            SET(nbitmask,(x+1),0);
            if( x == w-1 ) nbitmask = FIX(nbitmask);


            update(dp[!phase][nbitmask],(dp[phase][bitmask]+1));
          }
          
          // 0 x
          if( x+1 < w && field[y][x+1] != 1 ) {
            nbitmask = bitmask;
            SET(nbitmask,x,0);
            SET(nbitmask,(x+1),color);

            if( x == w-1 ) nbitmask = FIX(nbitmask);
            update(dp[!phase][nbitmask],(dp[phase][bitmask]+1));
          }
        }
        continue;
      Label2:;
        // x x
        if( !( GET(bitmask,x) && GET(bitmask,(x+1)) ) ) goto Label3;
        if( GET(bitmask,x) != GET(bitmask,(x+1)) ) goto Label3;

        color = GET(bitmask,x);
        
        // 0 0
        if( !STAR ) {
          nbitmask = bitmask;
          SET(nbitmask,x,0);
          SET(nbitmask,(x+1),0);
          if( x == w-1 ) nbitmask = FIX(nbitmask);
          update(dp[!phase][nbitmask],dp[phase][bitmask]+1);
        }
      Label3:;

      }
      if( field[y][x] == 2 || field[y][x] == 3 ) initter = false;
      rep(i,_size) dp[phase][state[i]] = -1;
      if( encounter >= 4 && dp[!phase][0] != -1 ) {
        mini = min(mini,dp[!phase][0]);
      }
      phase = !phase;
    }
  }
  if( dp[phase][0] != -1 ) mini = min(mini,dp[phase][0]);
  if( mini != IINF ) printf("%d\n",mini-2);
  else puts("0");
}

int main(){
  while( scanf("%d %d",&h,&w), h|w ){
    rep(i,h) rep(j,w) scanf("%d",&field[i][j]);
    compute();
  }
  return 0;
}

Measured memory_bytes: 9780