public static void main ( String arg [ ] ) {
  Scanner sc = new Scanner ( System . in ) ;
  int n = sc . nextInt ( ) ;
  int s = sc . nextInt ( ) ;
  int t = sc . nextInt ( ) ;
  int [ ] arr = new int [ n ] ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) arr [ i ] = sc . nextInt ( ) ;
  int [ ] arr2 = new int [ n ] ;
  s = s - 1 ;
  t = t - 1 ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    arr2 [ i ] = arr [ i ] - 1 ;
  }
  if ( s == t ) {
    System . out . println ( 0 ) ;
    System . exit ( 0 ) ;
  }
  int temp = s ;
  int i = 0 ;
  while ( i < n ) {
    temp = arr2 [ temp ] ;
    if ( temp == s ) {
      System . out . println ( - 1 ) ;
      System . exit ( 0 ) ;
    }
    i ++ ;
    if ( temp == t ) {
      System . out . println ( i ) ;
      break ;
    }
  }
  if ( temp != t ) System . out . println ( - 1 ) ;
}

public static void main ( String arg [ ] ) { Scanner sc = new Scanner ( System . in ) ; int n = sc . nextInt ( ) ; int s = sc . nextInt ( ) ; int t = sc . nextInt ( ) ; int [ ] arr = new int [ n ] ; for ( int i = 0 ; i < n ; i ++ ) arr [ i ] = sc . nextInt ( ) ; int [ ] arr2 = new int [ n ] ; s = s - 1 ; t = t - 1 ; for ( int i = 0 ; i < n ; i ++ ) { arr2 [ i ] = arr [ i ] - 1 ; } if ( s == t ) { System . out . println ( 0 ) ; System . exit ( 0 ) ; } int temp = s ; int i = 0 ; while ( i < n ) { temp = arr2 [ temp ] ; if ( temp == s ) { System . out . println ( - 1 ) ; System . exit ( 0 ) ; } i ++ ; if ( temp == t ) { System . out . println ( i ) ; break ; } } if ( temp != t ) System . out . println ( - 1 ) ; }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (type_identifier) name: (identifier) dimensions: (dimensions))) body: (block (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_identifier) arguments: (argument_list (field_access object: (identifier) field: (identifier)))))) (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: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (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: (array_type element: (integral_type) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (identifier))))) (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: (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))))) (local_variable_declaration type: (array_type element: (integral_type) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (identifier))))) (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal)))) (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (identifier) right: (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 (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal)))))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) consequence: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (decimal_integer_literal)))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (decimal_integer_literal)))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (identifier))) (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 (expression_statement (assignment_expression left: (identifier) right: (array_access array: (identifier) index: (identifier)))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) consequence: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (unary_expression operand: (decimal_integer_literal))))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (decimal_integer_literal)))))) (expression_statement (update_expression (identifier))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) consequence: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier)))) (break_statement))))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) consequence: (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (unary_expression operand: (decimal_integer_literal))))))))