26204번 - Displacing Particles 다국어

문제

A square has its vertices at the coordinates $(0, 0),ドル $(0, 2^N),ドル $(2^N , 2^N ),ドル $(2^N , 0)$. Each vertex has an attractor. A particle is placed initially at position $(2^{N-1} , 2^{N-1})$. Each attractor can be activated individually, any number of times. When an attractor at position $(i, j)$ is activated, if a particle is at position $(p, q),ドル it will be moved to the midpoint between $(i, j)$ and $(p, q)$.

Given $N$ and a point $(x, y),ドル calculate the least number of times you have to activate the attractors so that the particle ends up at position $(x, y)$.

입력

The input consists of a single line containing three integers $N,ドル $x$ and $y,ドル such that 1ドル ≤ N ≤ 20$ and 0ドル < x, y < 2^N$.

출력

Print a single line, containing the least number of times you have to active the attractors.

제한

힌트