public static void main ( String [ ] args ) {
  FastScanner fs = new FastScanner ( ) ;
  int n = fs . nextInt ( ) , a ;
  double d = 0.0 ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    a = fs . nextInt ( ) ;
    d += a ;
  }
  d /= n ;
  System . out . println ( String . format ( "%.12f" , d ) ) ;
}

public static void main ( String [ ] args ) { FastScanner fs = new FastScanner ( ) ; int n = fs . nextInt ( ) , a ; double d = 0.0 ; for ( int i = 0 ; i < n ; i ++ ) { a = fs . nextInt ( ) ; d += a ; } d /= n ; System . out . println ( String . format ( " % .12f " , d ) ) ; }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (array_type element: (type_identifier) dimensions: (dimensions)) name: (identifier))) body: (block (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_identifier) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) declarator: (variable_declarator name: (identifier))) (local_variable_declaration type: (floating_point_type) declarator: (variable_declarator name: (identifier) value: (decimal_floating_point_literal))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (expression_statement (assignment_expression left: (identifier) right: (identifier))))) (expression_statement (assignment_expression left: (identifier) right: (identifier))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (string_literal) (identifier))))))))