#include<iostream>
using namespace std;
int main()
{
	int a,S,sum=0,i=1,count=0;
	cin>>S;
	while(sum<S)
	{
		sum+=i++;
		count++;
	}
	a=sum-S;
	if(a%2==0);
    else if(a%2==1)
	{
	    if((sum+i-S)%2==0)
		count+=1;
	    else
		count+=2;
	}
	cout<<count;
	return 0;
}