There is k resistors, resistance of each of that is 1 Ohm. It is required to solder the circuit from them with common resistance r Ohm, where r – a rational number.
**Task.** What is the least number of resistors which is necessary for solution of this task?
**Notes.** Certainly it is supposed both consecutive and parallel connection, and their various combinations. In solving it is required to approximate the received value to within four signs after a comma.
**Stream.** The input stream sets number of resistors k and a demanded resistance of the circuit. The output stream – should specify the minimum number of resistors, or -1 if it is impossible to solder the necessary circuit.
Example Input stream: 7 3.5 Output stream: 5 |