public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  long p = sc . nextLong ( ) ;
  long d = sc . nextLong ( ) , ans = ++ p ;
  for ( long t = 10 ;
  ;
  t *= 10 ) {
    if ( p % t > d ) break ;
    ans = p - p % t ;
  }
  System . out . println ( ans - 1 ) ;
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; long p = sc . nextLong ( ) ; long d = sc . nextLong ( ) , ans = ++ p ; for ( long t = 10 ; ; t *= 10 ) { if ( p % t > d ) break ; ans = p - p % t ; } System . out . println ( ans - 1 ) ; }
(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)))))) (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))) declarator: (variable_declarator name: (identifier) value: (update_expression (identifier)))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) update: (assignment_expression left: (identifier) right: (decimal_integer_literal)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (identifier))) consequence: (break_statement)) (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (identifier) right: (binary_expression left: (identifier) right: (identifier))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (binary_expression left: (identifier) right: (decimal_integer_literal)))))))