x, y, h = map(int, input().split())
h = h / 1000
cnt = 0
minxy = min(x, y)
maxxy = max(x, y)
xylst = [minxy, maxxy]
for i in range(2):
    while xylst[i] > h:
        xylst[i] /= 2
        h *= 2
        cnt += 1

print(cnt)