x,y,h=map(int,input().split()) h=h/1000 ans=0 x,y=max(x,y),min(x,y) while x>h: if y>h: y=y/2 h=h*2 else: x=x/2 h=h*2 ans+=1 x,y=max(x,y),min(x,y) print(ans)