Red button, blue button

Yeongseon has two integers $a$ and $b$. Hyobin has a red button and a blue button.

Pressing the red button increases each of Yeongseon's two integers by 1. Pressing the blue button multiplies each of them by 2.

Hyobin wants to press buttons until $(a, b)$ becomes $(c, d)$. Write a program that finds the smallest number of button presses.

The first line contains four integers $a$, $b$, $c$, $d$. ($1 \le a, b, c, d \le 10^9$)

Print the smallest number of button presses that turns $(a, b)$ into $(c, d)$. If that is impossible, print -1.