poj 1844 Sum

Sum

Time Limit: 1000MS		Memory Limit: 30000K
Total Submissions: 8859		Accepted: 5756

Description

Consider the natural numbers from 1 to N. By associating to each number a sign (+ or -) and calculating the value of this expression we obtain a sum S. The problem is to determine for a given sum S the minimum number N for which we can obtain S by associating signs for all numbers between 1 to N.

For a given S, find out the minimum value N in order to obtain S according to the conditions of the problem.

Input

The only line contains in the first line a positive integer S (0< S <= 100000) which represents the sum to be obtained.

Output

The output will contain the minimum number N for which the sum S can be obtained.

Sample Input

12

Sample Output

7

Hint

The sum 12 can be obtained from at least 7 terms in the following way: 12 = -1+2+3+4+5+6-7.

#include<iostream>
using namespace std;
int main()
{
    int n;
    int i=0;
    int sum=0;
    cin>>n;
    while(1)
    {
        sum+=i;
        if(sum==n)
            break;
        if(sum>=n&&(sum-n)%2==0)
            break;
        else
            i++;
    }
    cout<<i<<endl;
    return 0;
}