x, y, h = map(int, input().split())
h /= 1000
ans = 0

for i in range(100):
    for g in range(100):
        ax = x*0.5**(i)
        ay = y*0.5**(g)
        ah = h*2**(i+g)
        if ax > ah and ay > ah:
            if ax > h*2 or ay > h*2:
                ans = max(ans, i+g+2)
            else:
                ans = max(ans, i+g+1)

print(ans)