public static void main ( String [ ] args ) {
  Scanner scanner = new Scanner ( System . in ) ;
  int n = scanner . nextInt ( ) ;
  int m = scanner . nextInt ( ) ;
  int sx = scanner . nextInt ( ) ;
  int sy = scanner . nextInt ( ) ;
  System . out . printf ( "%d %d\n" , sx , sy ) ;
  for ( int y = 1 ;
  y <= m ;
  y ++ ) {
    if ( y != sy ) {
      System . out . printf ( "%d %d\n" , sx , y ) ;
    }
  }
  int parity = 0 ;
  for ( int x = sx - 1 ;
  x >= 1 ;
  x -- ) {
    if ( parity % 2 == 0 ) {
      for ( int y = m ;
      y >= 1 ;
      y -- ) {
        System . out . printf ( "%d %d\n" , x , y ) ;
      }
    }
    else {
      for ( int y = 1 ;
      y <= m ;
      y ++ ) {
        System . out . printf ( "%d %d\n" , x , y ) ;
      }
    }
    parity ++ ;
  }
  parity = ( ( sx - 1 ) % 2 == 0 ) ? 1 : 0 ;
  for ( int x = sx + 1 ;
  x <= n ;
  x ++ ) {
    if ( parity % 2 == 0 ) {
      for ( int y = 1 ;
      y <= m ;
      y ++ ) {
        System . out . printf ( "%d %d\n" , x , y ) ;
      }
    }
    else {
      for ( int y = m ;
      y >= 1 ;
      y -- ) {
        System . out . printf ( "%d %d\n" , x , y ) ;
      }
    }
    parity ++ ;
  }
  scanner . close ( ) ;
}

public static void main ( String [ ] args ) { Scanner scanner = new Scanner ( System . in ) ; int n = scanner . nextInt ( ) ; int m = scanner . nextInt ( ) ; int sx = scanner . nextInt ( ) ; int sy = scanner . nextInt ( ) ; System . out . printf ( " % d ▁ % d \n " , sx , sy ) ; for ( int y = 1 ; y <= m ; y ++ ) { if ( y != sy ) { System . out . printf ( " % d ▁ % d \n " , sx , y ) ; } } int parity = 0 ; for ( int x = sx - 1 ; x >= 1 ; x -- ) { if ( parity % 2 == 0 ) { for ( int y = m ; y >= 1 ; y -- ) { System . out . printf ( " % d ▁ % d \n " , x , y ) ; } } else { for ( int y = 1 ; y <= m ; y ++ ) { System . out . printf ( " % d ▁ % d \n " , x , y ) ; } } parity ++ ; } parity = ( ( sx - 1 ) % 2 == 0 ) ? 1 : 0 ; for ( int x = sx + 1 ; x <= n ; x ++ ) { if ( parity % 2 == 0 ) { for ( int y = 1 ; y <= m ; y ++ ) { System . out . printf ( " % d ▁ % d \n " , x , y ) ; } } else { for ( int y = m ; y >= 1 ; y -- ) { System . out . printf ( " % d ▁ % d \n " , x , y ) ; } } parity ++ ; } scanner . close ( ) ; }
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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 (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (string_literal) (identifier) (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 (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) 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