import java.util.*;


class Solution {
    public int brokenCalc(int X, int Y) {
        List<Integer> isVisited = new ArrayList<Integer>();
        Queue<Integer> Q = new LinkedList<Integer>();
        Q.add(X);
        int num = runBFS(Y, Q, isVisited);
        return num;
    }

    private int runBFS(int Y, Queue<Integer> Q, List<Integer> isVisited) {
        int numNodesInCurrLevel = 1;
        int numNodesNextLevel = 0;
        int level = 0;
        while (!Q.isEmpty()) {
            int X = Q.remove();
            //System.out.println("X " + X + " " + level);
            if (X == Y) {
                break;
            }
            isVisited.add(X);
            numNodesInCurrLevel--;
            if (X > 1) {
                if (!isVisited.contains(X-1)) {
                    Q.add(X - 1);
                    numNodesNextLevel++;
                }
            }
            if (X < Y) {
                if (!isVisited.contains(2*X)) {
                    Q.add(2*X);
                    numNodesNextLevel++;
                }
            }
            if (numNodesInCurrLevel == 0) {
                numNodesInCurrLevel = numNodesNextLevel;
                numNodesNextLevel = 0;
                level++;
            }
        }
        return level;
    }

}