#ifdef DEBUG
  #define _GLIBCXX_DEBUG
  #define CERR( ANSWER ) cerr << ANSWER << "\n";
#else
  #pragma GCC optimize ( "O3" )
  #pragma GCC optimize( "unroll-loops" )
  #pragma GCC target ( "sse4.2,fma,avx2,popcnt,lzcnt,bmi2" )
  #define CERR( ANSWER ) 
#endif
#include <bits/stdc++.h>
using namespace std;
using ll = long long;

#define TYPE_OF( VAR ) remove_const<remove_reference<decltype( VAR )>::type >::type
#define UNTIE ios_base::sync_with_stdio( false ); cin.tie( nullptr )
#define CEXPR( LL , BOUND , VALUE ) constexpr const LL BOUND = VALUE
#define CIN( LL , A ) LL A; cin >> A
#define ASSERT( A , MIN , MAX ) assert( ( MIN ) <= A && A <= ( MAX ) )
#define CIN_ASSERT( A , MIN , MAX ) CIN( TYPE_OF( MAX ) , A ); ASSERT( A , MIN , MAX )
#define FOR( VAR , INITIAL , FINAL_PLUS_ONE ) for( TYPE_OF( FINAL_PLUS_ONE ) VAR = INITIAL ; VAR < FINAL_PLUS_ONE ; VAR ++ )
#define FOREQ( VAR , INITIAL , FINAL ) for( TYPE_OF( FINAL ) VAR = INITIAL ; VAR <= FINAL ; VAR ++ )
#define FOREQINV( VAR , INITIAL , FINAL ) for( TYPE_OF( INITIAL ) VAR = INITIAL ; VAR >= FINAL ; VAR -- )
#define FOR_ITR( ARRAY , ITR , END ) for( auto ITR = ARRAY .begin() , END = ARRAY .end() ; ITR != END ; ITR ++ )
#define REPEAT( HOW_MANY_TIMES ) FOR( VARIABLE_FOR_REPEAT , 0 , HOW_MANY_TIMES )
#define QUIT return 0
#define COUT( ANSWER ) cout << ( ANSWER ) << "\n"
#define RETURN( ANSWER ) COUT( ANSWER ); QUIT

int main()
{
  UNTIE;
  CEXPR( int , bound_N , 200000 );
  CIN_ASSERT( N , 1 , bound_N );
  CEXPR( int , bound_ABi , 1000000000 );
  static set<int> AB[bound_N] = {};
  map<int,set<int> > Cmin{};
  FOR( i , 0 , N ){
    CIN_ASSERT( Ai , 0 , bound_ABi );
    assert( Ai % 2 == 0 );
    AB[i].insert( Ai );
    Cmin[Ai].insert( i );
  }
  int Cmax = 0;
  FOR( i , 0 , N ){
    CIN_ASSERT( Bi , 0 , bound_ABi );
    assert( Bi % 2 == 0 );
    set<int>& ABi = AB[i];
    const int& Ai = *ABi.begin();
    int mid = ( Ai + Bi ) / 2;
    ABi.insert( mid );
    Cmin[mid].insert( i );
    ABi.insert( Bi );
    Cmin[Bi].insert( i );
    Ai < Bi ? Cmax < Ai ? Cmax = Ai : Cmax : Cmax < Bi ? Cmax = Bi : Cmax;
  }
  int answer = bound_ABi;
  auto itr_Cmin = Cmin.begin();
  while( ! Cmin.empty() ){
    int temp = Cmax - itr_Cmin->first;
    CERR( Cmax << "-" << itr_Cmin->first << "=" << temp );
    answer > temp ? answer = temp : answer;
    FOR_ITR( itr_Cmin->second , itr_i , end_i ){
      set<int>& ABi = AB[*itr_i];
      if( ABi.size() == 1 ){
	RETURN( answer );
      }
      auto itr_ABi = ABi.begin();
      itr_ABi = ABi.erase( itr_ABi );
      CERR( Cmax << "<" << *itr_ABi << "?" );
      Cmax < *itr_ABi ? Cmax = *itr_ABi : Cmax;
    }
    itr_Cmin = Cmin.erase( itr_Cmin );
  }
  QUIT;
}