#include <stdio.h>

#define N 7

/** Application main entry point. */
int
main (
  int     argc,
  char  * argv[ ]
  )
{
  int n;
  int i;

  while ( scanf ( " %d", &n ) == 1 )
  {
    int d[ N ] = { 0 };
    int oc = 0;

    for ( i = 0; i < n; ++i )
    {
      char s[ 8 ];

      scanf ( " %s", s );
      ++d[ s[ 0 ] - '0' ];
      ++d[ s[ 1 ] - '0' ];
    }

    for ( i = 0; i < N; ++i )
    {
      oc += !!( d[ i ] % 2 );
    }

    puts ( oc > 2 ? "No" : "Yes" );
  }

  return ( 0 );
}