public static void main ( String [ ] args ) throws Exception {
  FastReader sc = new FastReader ( ) ;
  int n = sc . nextInt ( ) ;
  double p [ ] = new double [ n ] ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    p [ i ] = sc . nextDouble ( ) ;
    if ( p [ i ] == 1 ) {
      System . out . println ( 1 ) ;
      return ;
    }
  }
  Arrays . sort ( p ) ;
  double max = 0 ;
  for ( int i = n - 1 ;
  i >= 0 ;
  i -- ) {
    double pr = 1 ;
    double sum = 0 ;
    for ( int j = i ;
    j < n ;
    j ++ ) {
      pr *= ( 1D - p [ j ] ) ;
    }
    for ( int j = i ;
    j < n ;
    j ++ ) {
      sum += ( pr / ( 1 - p [ j ] ) ) * ( p [ j ] ) ;
    }
    max = Math . max ( max , sum ) ;
  }
  System . out . println ( max ) ;
}

public static void main ( String [ ] args ) throws Exception { FastReader sc = new FastReader ( ) ; int n = sc . nextInt ( ) ; double p [ ] = new double [ n ] ; for ( int i = 0 ; i < n ; i ++ ) { p [ i ] = sc . nextDouble ( ) ; if ( p [ i ] == 1 ) { System . out . println ( 1 ) ; return ; } } Arrays . sort ( p ) ; double max = 0 ; for ( int i = n - 1 ; i >= 0 ; i -- ) { double pr = 1 ; double sum = 0 ; for ( int j = i ; j < n ; j ++ ) { pr *= ( 1D - p [ j ] ) ; } for ( int j = i ; j < n ; j ++ ) { sum += ( pr / ( 1 - p [ j ] ) ) * ( p [ j ] ) ; } max = Math . max ( max , sum ) ; } System . out . println ( max ) ; }
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