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Time Limit: 3.0 Seconds Memory Limit: 65536K

Total Runs: 1885 Accepted Runs: 923

The Recaman's sequence is defined by a^{0} = 0 ; for m > 0,
a^{m} = a^{m-1} - m if the resulting a^{m} is positive
and not already in the sequence, otherwise a^{m} = a^{m-1} + m.

The first few numbers in the Recaman's Sequence is 0, 1, 3, 6, 2, 7, 13, 20, 12, 21, 11, 22, 10, 23, 9... .
Given k, your task is to calculate a^{k}.

**Input**

The input consists of several test cases. Each line of the input contains an integer k where 0 ≤ k ≤ 500000. The last line contains an integer -1, which should not be processed.

**Output**

For each k given in the input, print one line containing a^{k} to the output.

**Sample Input**

7 10000 -1

**Sample Output**

20 18658

Maintance:Fxz. Developer: SuperHacker, G.D.Retop, Fxz