Poj Solution 1844

http://poj.org/problem?id=1844

//* @author: 82638882@163.com
import java.util.*;
public class Main
{
 public static void main(String[] args)
 {
  Scanner in=new Scanner(System.in);
  int sun=in.nextInt();
  int sum=0;
  int i;
  for(i=1;i< 9999;i++)
  {
    sum+=i;
    if (sum>=sun)break;
  }
  if((sum-sun)%2==0) System.out.println(i);
  else if((sum-sun)%2==1&&i%2==1) System.out.println(i+2);
  else if((sum-sun)%2==1&&i%2==0) System.out.println(i+1);
 }
}