Description

Snail climbing a well problem: A snail needs to climb to the top of a tree stump that is $v$ meters high. Every day, it climbs up $a$ meters during the day, and slips down $b$ meters at night. After how many days can it reach the top of the stump?

Input Format

One line with three integers $a$, $b$, and $v$, separated by spaces.

Output Format

One line with one integer, the answer.

2 1 5

4

5 1 6

2

100 99 1000000000

999999901

Hint

Constraints

For $100\%$ of the testdata, it is guaranteed that $1 \leq b < a \leq v \leq 1 \times 10^9$.

Notes

• This problem is worth $30$ points in total.
• Translated from COCI2010-2011 CONTEST #2 PUŽ. Translator:
  https://www.luogu.com.cn/user/115711

Hint

Please derive the formula for the result. A simple simulation may cause TLE.

Translated by ChatGPT 5