#include<bits/stdc++.h>
using namespace std;

#define UNTIE ios_base::sync_with_stdio( false ); cin.tie( nullptr ) 
#define CIN( LL , A ) LL A; cin >> A 
#define TYPE_OF( VAR ) remove_const<remove_reference<decltype( VAR )>::type >::type
#define FOREQ( VAR , INITIAL , FINAL ) for( TYPE_OF( FINAL ) VAR = INITIAL ; VAR <= FINAL ; VAR ++ )  
#define QUIT return 0 
#define RETURN( ANSWER ) cout << ( ANSWER ) << "\n"; QUIT 

template <typename T> inline T Absolute( const T& a ){ return a > 0 ? a : - a; }

int main()
{
  UNTIE;
  CIN( int , N );
  assert( 1 <= N && N <= 10 );
  CIN( int , S );
  assert( 1 <= S && S <= 10 );
  CIN( int , K );
  assert( 0 <= K && K <= 10 );
  int R;
  int opt = K + 1;
  int opt_current;
  int Ai;
  FOREQ( i , 1 , N ){
    cin >> Ai;
    opt_current = Absolute( Ai - S );
    if( opt_current < opt ){
      R = i;
      opt = opt_current;
    }
  }
  if( opt <= K ){
    RETURN( R );
  }
  RETURN( "Unlucky!" );
}