public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  int n = sc . nextInt ( ) ;
  int k = sc . nextInt ( ) ;
  int out = 0 ;
  while ( n -- > 0 ) {
    int l = sc . nextInt ( ) ;
    int r = sc . nextInt ( ) ;
    out += r - l + 1 ;
  }
  if ( out <= k ) System . out . println ( k - out ) ;
  else {
    int num = ( int ) Math . ceil ( ( double ) out / ( double ) k ) ;
    k *= num ;
    System . out . println ( k - out ) ;
  }
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; int n = sc . nextInt ( ) ; int k = sc . nextInt ( ) ; int out = 0 ; while ( n -- > 0 ) { int l = sc . nextInt ( ) ; int r = sc . nextInt ( ) ; out += r - l + 1 ; } if ( out <= k ) System . out . println ( k - out ) ; else { int num = ( int ) Math . ceil ( ( double ) out / ( double ) k ) ; k *= num ; System . out . println ( k - out ) ; } }
(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)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (while_statement condition: (parenthesized_expression (binary_expression left: (update_expression (identifier)) right: (decimal_integer_literal))) body: (block (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)))) (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (decimal_integer_literal)))))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) consequence: (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (binary_expression left: (identifier) right: (identifier))))) alternative: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (cast_expression type: (integral_type) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (cast_expression type: (floating_point_type) value: (identifier)) right: (cast_expression type: (floating_point_type) value: (identifier)))))))) (expression_statement (assignment_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: (identifier)))))))))