#include <iostream>
#include <cmath>
#include <stdio.h>
using namespace std;

int main() {
	int m;
	scanf("%d", &m);
	double n_ = (-1+sqrt(1.0+8*m))/2;
	int n = (int) n_;
	if(abs(n_-n) > 1e-6) n++;
	for(int nn = n; ; nn++){
		if((nn*(nn+1)/2-m)%2 == 0){
			printf("%d\n", nn);
			break;
		}
	}
	return 0;
}