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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.

Input

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

Output

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

Sample test(s)