# Queens

Time Limit: 2000/1000 MS (Java/Others)

Memory Limit: 32768/32768 K (Java/Others)

## Description

Everyone knows about the "eight queens problem", but today you will solve a different one.
We are given triangle lattice of side n, as shown in the Figure below. A queen on the lattice can move along a straight line parallel to any of the sides of the triangle. How many queens can be placed on the lattice at most, without any two queens attacking each other?

## Input

Each test case contains a single integer N (1<=N<=10^10), indicating the side of the triangle. The input is terminated by a set starting with N = 0. This set should not be processed.

## Output

For each test case, output on a line the number of the queens can be placed on the lattice without any two queens attacking each other.

## Sample Input

1
2
0

## Sample Output

1
1

lcy

## Source

HDU 2009-4 Programming Contest