x, y, h = map(int, input().split())
x, y = 1000 * x, 1000 * y
tempx, tempy, temph = x, y, h

ans1, ans2 = 0, 0
while y > h:
    ans1 += 1
    h *= 4
    x *= 2
while x > h:
    ans1 += 1
    h *= 4
    y *= 2

x, y, h = tempx, tempy, temph
while x > h:
    ans2 += 1
    h *= 4
    y *= 2
while y > h:
    ans2 += 1
    h *= 4
    x *= 2
    
print(max(ans1, ans2))