public static void main ( String [ ] args ) {
  FastScanner fs = new FastScanner ( ) ;
  int n = fs . nextInt ( ) ;
  ArrayList < Integer > a = new ArrayList < > ( ) ;
  int len = 0 ;
  int curr = 0 ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    int b = fs . nextInt ( ) ;
    a . add ( b ) ;
    if ( b == 0 ) {
      len = Math . max ( len , curr ) ;
      curr = 0 ;
    }
    else {
      curr ++ ;
    }
  }
  for ( int b : a ) {
    if ( b == 0 ) {
      len = Math . max ( len , curr ) ;
      curr = 0 ;
    }
    else {
      curr ++ ;
    }
  }
  System . out . println ( len ) ;
}

public static void main ( String [ ] args ) { FastScanner fs = new FastScanner ( ) ; int n = fs . nextInt ( ) ; ArrayList < Integer > a = new ArrayList < > ( ) ; int len = 0 ; int curr = 0 ; for ( int i = 0 ; i < n ; i ++ ) { int b = fs . nextInt ( ) ; a . add ( b ) ; if ( b == 0 ) { len = Math . max ( len , curr ) ; curr = 0 ; } else { curr ++ ; } } for ( int b : a ) { if ( b == 0 ) { len = Math . max ( len , curr ) ; curr = 0 ; } else { curr ++ ; } } System . out . println ( len ) ; }
(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)))) (local_variable_declaration type: (generic_type (type_identifier) (type_arguments (type_identifier))) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (generic_type (type_identifier) (type_arguments)) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_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 (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier) (identifier))))) (expression_statement (assignment_expression left: (identifier) right: (decimal_integer_literal)))) alternative: (block (expression_statement (update_expression (identifier))))))) (enhanced_for_statement type: (integral_type) name: (identifier) value: (identifier) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier) (identifier))))) (expression_statement (assignment_expression left: (identifier) right: (decimal_integer_literal)))) alternative: (block (expression_statement (update_expression (identifier))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))