public static void main ( String [ ] args ) {
  String s = "abcab" ;
  String ans = longestPrefixSuffix ( s ) ;
  if ( ans == "" ) System . out . println ( "-1" ) ;
  else System . out . println ( ans ) ;
}

public static void main ( String [ ] args ) { String s = " abcab " ; String ans = longestPrefixSuffix ( s ) ; if ( ans == " " ) System . out . println ( " - 1" ) ; else System . out . println ( ans ) ; }
(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: (string_literal))) (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (method_invocation name: (identifier) arguments: (argument_list (identifier))))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (string_literal))) consequence: (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (string_literal)))) alternative: (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier)))))))