public static void main ( String [ ] args ) {
  Scanner in = new Scanner ( System . in ) ;
  int R = in . nextInt ( ) ;
  int C = in . nextInt ( ) ;
  int SR = in . nextInt ( ) ;
  int SC = in . nextInt ( ) ;
  StringBuilder output = new StringBuilder ( ) ;
  output . append ( SR ) . append ( ' ' ) . append ( SC ) . append ( '\n' ) ;
  for ( int c = 1 ;
  c <= C ;
  c ++ ) {
    if ( c != SC ) {
      output . append ( SR ) . append ( ' ' ) . append ( c ) . append ( '\n' ) ;
    }
  }
  int lastC = C ;
  for ( int r = 1 ;
  r <= R ;
  r ++ ) {
    if ( r != SR ) {
      if ( lastC == 1 ) {
        for ( int c = 1 ;
        c <= C ;
        c ++ ) {
          output . append ( r ) . append ( ' ' ) . append ( c ) . append ( '\n' ) ;
        }
        lastC = C ;
      }
      else {
        for ( int c = C ;
        c >= 1 ;
        c -- ) {
          output . append ( r ) . append ( ' ' ) . append ( c ) . append ( '\n' ) ;
        }
        lastC = 1 ;
      }
    }
  }
  System . out . print ( output ) ;
}

public static void main ( String [ ] args ) { Scanner in = new Scanner ( System . in ) ; int R = in . nextInt ( ) ; int C = in . nextInt ( ) ; int SR = in . nextInt ( ) ; int SC = in . nextInt ( ) ; StringBuilder output = new StringBuilder ( ) ; output . append ( SR ) . append ( ' ▁ ' ) . append ( SC ) . append ( ' \n ' ) ; for ( int c = 1 ; c <= C ; c ++ ) { if ( c != SC ) { output . append ( SR ) . append ( ' ▁ ' ) . append ( c ) . append ( ' \n ' ) ; } } int lastC = C ; for ( int r = 1 ; r <= R ; r ++ ) { if ( r != SR ) { if ( lastC == 1 ) { for ( int c = 1 ; c <= C ; c ++ ) { output . append ( r ) . append ( ' ▁ ' ) . append ( c ) . append ( ' \n ' ) ; } lastC = C ; } else { for ( int c = C ; c >= 1 ; c -- ) { output . append ( r ) . append ( ' ▁ ' ) . append ( c ) . append ( ' \n ' ) ; } lastC = 1 ; } } } System . out . print ( output ) ; }
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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)))) (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_identifier) arguments: (argument_list)))) (expression_statement (method_invocation object: (method_invocation object: (method_invocation object: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))) name: (identifier) arguments: (argument_list (character_literal))) name: (identifier) arguments: (argument_list (identifier))) name: (identifier) arguments: (argument_list (character_literal)))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: 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arguments: (argument_list (character_literal)))))) (expression_statement (assignment_expression left: (identifier) right: (identifier)))) alternative: (block (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (identifier))) condition: (binary_expression left: (identifier) right: (decimal_integer_literal)) update: (update_expression (identifier)) body: (block (expression_statement (method_invocation object: (method_invocation object: (method_invocation object: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))) name: (identifier) arguments: (argument_list (character_literal))) name: (identifier) arguments: (argument_list (identifier))) name: (identifier) arguments: (argument_list (character_literal)))))) (expression_statement (assignment_expression left: (identifier) right: (decimal_integer_literal))))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))