Bottle Deposits

Source: Phước Hưng OJ

Version: Phuoc Hung OJ Extended

Problem Statement

Each small bottle returns 0.10 monetary units and each large bottle returns 0.25. Compute the total refund and display exactly two decimal places. The rates are defined for this PHOJ edition.

Input

One line with integers $a,b$: numbers of small and large bottles.

Output

Print the total refund with exactly two decimal places.

Subtask

• Subtask 1 — 100 points: $0\le a,b\le10^6$.

Example

Input

3 2

Output

0.80

Explanation

Three small bottles return $3\times0.10=0.30$ and two large bottles return $2\times0.25=0.50$. Total: $0.80$.