x, y, h = map(int, input().split())
x *= 10**3
y *= 10**3
x, y = min(x, y), max(x, y)

ans = 0
while x > h:
    x /= 2
    h *= 2
    ans += 1

while y > h:
    y /= 2
    h *= 2
    ans += 1
print(ans)