static int longest_substring ( String s , int k ) {
  int n = s . length ( ) ;
  if ( k > 1 ) {
    s += s ;
    n *= 2 ;
  }
  int ans = 0 ;
  int i = 0 ;
  while ( i < n ) {
    int x = 0 ;
    while ( i < n && s . charAt ( i ) == '0' ) {
      x ++ ;
      i ++ ;
    }
    ans = Math . max ( ans , x ) ;
    i ++ ;
  }
  if ( k == 1 || ans != n ) return ans ;
  else return ( ans / 2 ) * k ;
}

static int longest_substring ( String s , int k ) { int n = s . length ( ) ; if ( k > 1 ) { s += s ; n *= 2 ; } int ans = 0 ; int i = 0 ; while ( i < n ) { int x = 0 ; while ( i < n && s . charAt ( i ) == '0' ) { x ++ ; i ++ ; } ans = Math . max ( ans , x ) ; i ++ ; } if ( k == 1 || ans != n ) return ans ; else return ( ans / 2 ) * k ; }
(method_declaration (modifiers) type: (integral_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (type_identifier) name: (identifier)) (formal_parameter type: (integral_type) name: (identifier))) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (identifier))) (expression_statement (assignment_expression left: (identifier) right: (decimal_integer_literal))))) (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))) (while_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (while_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))) right: (character_literal)))) body: (block (expression_statement (update_expression (identifier))) (expression_statement (update_expression (identifier))))) (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier) (identifier))))) (expression_statement (update_expression (identifier))))) (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (decimal_integer_literal)) right: (binary_expression left: (identifier) right: (identifier)))) consequence: (return_statement (identifier)) alternative: (return_statement (binary_expression left: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (identifier))))))