#include using namespace std; typedef long long ll; typedef vector< int > vi; typedef vector< vi > vvi; typedef vector< ll > vl; typedef vector< vl > vvl; typedef pair< int, int > pii; typedef vector< pii > vp; typedef vector< double > vd; typedef vector< vd > vvd; typedef vector< string > vs; template< class T1, class T2 > int upmin( T1 &x, T2 v ){ if( x > v ){ x = v; return 1; } return 0; } template< class T1, class T2 > int upmax( T1 &x, T2 v ){ if( x < v ){ x = v; return 1; } return 0; } const int INF = 0x3f3f3f3f; int H, W; vvi G; void init(){ cin >> H >> W; G = vvi( H, vi( W ) ); for( int i = 0; i < H; ++i ) for( int j = 0; j < W; ++j ) cin >> G[ i ][ j ]; } int dp[ 100 + 1 ][ 100 + 1 ][ 9 + 1 ][ 9 + 1 ]; int kado( int a, int b, int c ){ if( a == 0 ) return 1; if( a == b or b == c or c == a ) return 0; return b == min( { a, b, c } ) or b == max( { a, b, c } ); } void preprocess(){ memset( dp, INF, sizeof( dp ) ); queue< tuple< int, int, int, int > > que; dp[ 0 ][ 0 ][ 0 ][ G[ 0 ][ 0 ] ] = 0; que.emplace( 0, 0, 0, G[ 0 ][ 0 ] ); while( not que.empty() ){ int x, y, a, b; tie( x, y, a, b ) = que.front(); que.pop(); const int dx[] = { 0, 1, 0, -1 }; const int dy[] = { 1, 0, -1, 0 }; for( int di = 0; di < 4; ++di ){ int nx = x + dx[ di ]; int ny = y + dy[ di ]; if( not ( 0 <= nx and nx < H and 0 <= ny and ny < W ) ) continue; if( not kado( a, b, G[ nx ][ ny ] ) ) continue; int na = b; int nb = G[ nx ][ ny ]; if( dp[ nx ][ ny ][ na ][ nb ] < INF ) continue; dp[ nx ][ ny ][ na ][ nb ] = dp[ x ][ y ][ a ][ b ] + 1; que.emplace( nx, ny, na, nb ); } } } void solve(){ int ans = INF; for( int i = 0; i <= 9; ++i ) for( int j = 0; j <= 9; ++j ) upmin( ans, dp[ H - 1 ][ W - 1 ][ i ][ j ] ); if( ans == INF ) cout << -1 << endl; else cout << ans << endl; } signed main(){ ios::sync_with_stdio( 0 ); init(); preprocess(); solve(); return 0; }