from collections import deque
def BFS(a, b):
queue = deque()
queue.append([b, 1])
visited = set()
visited.add(b)
while queue:
current_number, count = queue.popleft()
if current_number == a:
return count
if current_number % 2 == 0:
next_number = current_number // 2
if next_number not in visited:
queue.append([next_number, count + 1])
visited.add(next_number)
if current_number % 10 == 1:
next_number = (current_number - 1) // 10
if next_number not in visited:
queue.append([next_number, count + 1])
visited.add(next_number)
return -1
A, B = map(int, input().split())
print(BFS(A, B))
