public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  n = sc . nextInt ( ) ;
  int m = sc . nextInt ( ) ;
  a = new boolean [ n ] [ n ] ;
  for ( int i = 0 ;
  i < m ;
  i ++ ) {
    int x = sc . nextInt ( ) - 1 ;
    int y = sc . nextInt ( ) - 1 ;
    a [ x ] [ y ] = true ;
  }
  System . out . println ( solve ( 0 , 0 ) ) ;
  sc . close ( ) ;
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; n = sc . nextInt ( ) ; int m = sc . nextInt ( ) ; a = new boolean [ n ] [ n ] ; for ( int i = 0 ; i < m ; i ++ ) { int x = sc . nextInt ( ) - 1 ; int y = sc . nextInt ( ) - 1 ; a [ x ] [ y ] = true ; } System . out . println ( solve ( 0 , 0 ) ) ; sc . close ( ) ; }
(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 (field_access object: (identifier) field: (identifier)))))) (expression_statement (assignment_expression left: (identifier) right: (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)))) (expression_statement (assignment_expression left: (identifier) right: (array_creation_expression type: (boolean_type) dimensions: (dimensions_expr (identifier)) 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: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) right: (decimal_integer_literal)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) right: (decimal_integer_literal)))) (expression_statement (assignment_expression left: (array_access array: (array_access array: (identifier) index: (identifier)) index: (identifier)) right: (true))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (method_invocation name: (identifier) arguments: (argument_list (decimal_integer_literal) (decimal_integer_literal)))))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))))