PUŽ

문제

There is a snail on the ground. It wants to climb to the top of a wooden pole with the height of V meters, measuring from the ground level. In one day it can climb A meters upwards, however during each night it sleeps, sliding B meters back down. Determine the number of days it needs to climb to the top. 

입력

The first and only line of input contains three integers separated by a single space: A, B, and V (1 ≤ B < A ≤ V ≤ 1 000 000 000), with meanings described above. 

출력

The first and only line of output must contain the number of days that the snail needs to reach the top.