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Solomon Golomb sequence 
http://www.programming-challenges.com/pg.php?page=downloadproblem&probid=110607&format=html
Solomon Golomb's self-describing sequence （ f (1), f (2), f (3),...） is the only non-decreasing sequence of positive integers with the property that it contains exactly f (k) occurrences of k for each k. A few moment's thought reveals that the sequence must begin as follows:

n 1 2 3 4 5 6 7 8 9 10 11 12
f (n) 1 2 2 3 3 4 4 4 5 5 5 6

In this problem you are expected to write a program that calculates the value of f (n) given the value of n.

Input

The input may contain multiple test cases. Each test case occupies a separate line and contains an integer n ( 1<=$n<=2, 000, 000, 000). The input terminates with a test case containing a value 0 for n and this case must not be processed.

Output

For each test case in the input, output the value of f (n) on a separate line.

Sample Input

100
9999
123456
1000000000
0

Sample Output

21
356
1684
438744