Problem A. Asphalt ≡

Statement

Young road constructor Vasya decided to pave a road with asphalt. The road is a straight line segment L meters long.

Vasya can pave a continuous segment of A meters of road per day. To avoid potential cracks on the borders between segments paved on different days, Vasya decided to overlap segments. Specifically:

• On the first day, Vasya paves first A meters.
• On the second day, Vasya moves back B meters, and paves A meters starting from that point.
• This process is repeated until the whole road is paved.
• Vasya stops paving as soon as the last meter of the road is paved, even if he paved less than A meters at the last day.

Your program must calculate the total number of meters that Vasya will pave.

Input format

Input contains three integers L A B.

Output format

Output must contain a single integer — the total number of meters paved.

Constraints

1 ≤ L, A, B ≤ 100

A > B

Sample tests

10 5 3

19

4 5 3

4

5 5 3

5