Cakes — Eolymp

Input

The input consists of a single line containing two integers $n$ and $k$ ( $1 \leq n, k \leq 1 0^{18}$ 1 \le n, k \le 10^{18}), where $n$ is the number of cakes to be purchased and $k$ is the number of coins required for the second type of purchase.

Output

Output a single integer representing the minimum number of coins needed to buy exactly $n$ cakes.

Examples

Example 1

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Example 2

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Note

In the first example, Vitaliy can buy 3 cakes for 2 coins and then buy 1 cake twice for 1 coin each. This results in a total of $2 + 1 + 1 = 4$ 2 + 1 + 1 = 4 coins.

In the second example, Vitaliy can simply buy 1 cake for 1 coin.

Scoring

Solutions that correctly handle the constraints $1 \leq n, k \leq 1 0^{5}$ 1 \le n, k \le 10^5 will earn 20% of the total points.