#include<iostream>using namespace std;int tran[ 10 ][ 20 ], N, M;struct Command{ int command; int pre;};const int MAX = 200000;Command cmdList[ MAX ]; int cCount;int queue[ MAX ][ 8 ], front, rear;int cmds[ MAX ], cmdSize;char xx[ 17 ] = "0123456789abcdef";void read(){ scanf( "%d %d", &N, &M ); int i, j; for ( i = 0; i < N; i ++ ) { for ( j = 0; j < M; j ++ ) scanf( "%d", &tran[ i ][ j ] ); queue[ 0 ][ i ] = i; }}bool checkCurState( int front, int size ){ for ( int i = 0; i < size; i ++ ) if ( queue[ front ][ i ] != 0 ) return false; return true;}bool checkHaveUsed( int cur, int curState[], int size ){ for ( int x = cur; x != 0; x = cmdList[ x ].pre ) { bool flag = false; for ( int i = 0; i < size; i ++ ) if ( curState[ i ] != queue[ x ][ i ] ) flag = true; if ( !flag ) return true; } return false;}void getPath( int front ){ cmdSize = 0; for ( int x = front; x != 0; x = cmdList[ x ].pre ) cmds[ cmdSize ++ ] = cmdList[ x ].command;}bool bfs(){ front = 0; rear = 1; while( front < rear ) { if ( checkCurState( front, N ) ) { getPath( front ); return true; } for ( int i = 0; i < M; i ++ ) { for ( int j = 0; j < N; j ++ ) queue[ rear ][ j ] = tran[ queue[ front ][ j ] ][ i ]; if ( !checkHaveUsed( front, queue[ rear ], N ) ) { cmdList[ rear ].command = i; cmdList[ rear ].pre = front; rear ++; } } front ++; } return false;}void print( int size ){ for ( int i = size - 1; i >= 0; i -- ) printf( "%c", xx[ cmds[ i ] ]); putchar( 'n' );}int main(){ read(); if ( bfs() ) print( cmdSize ); else printf( "*n" ); return 0;}
