public static void main ( String args [ ] ) {
  Scanner sc = new Scanner ( System . in ) ;
  String [ ] S = new String [ 8 ] ;
  boolean check = true ;
  for ( int i = 0 ;
  i < 8 ;
  i ++ ) {
    S [ i ] = sc . next ( ) ;
    for ( int j = 0 ;
    j < 7 ;
    j ++ ) {
      if ( S [ i ] . charAt ( j ) == S [ i ] . charAt ( j + 1 ) ) check = false ;
    }
  }
  if ( check ) System . out . println ( "YES" ) ;
  else System . out . println ( "NO" ) ;
}

public static void main ( String args [ ] ) { Scanner sc = new Scanner ( System . in ) ; String [ ] S = new String [ 8 ] ; boolean check = true ; for ( int i = 0 ; i < 8 ; i ++ ) { S [ i ] = sc . next ( ) ; for ( int j = 0 ; j < 7 ; j ++ ) { if ( S [ i ] . charAt ( j ) == S [ i ] . charAt ( j + 1 ) ) check = false ; } } if ( check ) System . out . println ( " YES " ) ; else System . out . println ( " NO " ) ; }
(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: (array_type element: (type_identifier) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (array_creation_expression type: (type_identifier) dimensions: (dimensions_expr (decimal_integer_literal))))) (local_variable_declaration type: (boolean_type) declarator: (variable_declarator name: (identifier) value: (true))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (decimal_integer_literal)) update: (update_expression (identifier)) body: (block (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (decimal_integer_literal)) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (method_invocation object: (array_access array: (identifier) index: (identifier)) name: (identifier) arguments: (argument_list (identifier))) right: (method_invocation object: (array_access array: (identifier) index: (identifier)) name: (identifier) arguments: (argument_list (binary_expression left: (identifier) right: (decimal_integer_literal)))))) consequence: (expression_statement (assignment_expression left: (identifier) right: (false)))))))) (if_statement condition: (parenthesized_expression (identifier)) consequence: (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (string_literal)))) alternative: (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (string_literal)))))))