#include <stdio.h>

unsigned long long int sankaku(unsigned long long int x){return (x*(x+1))/2;}
unsigned long long int gcd(unsigned long long int x,unsigned long long int y){int z;while(y){z=x%y;x=y;y=z;}return x;}

int main(void) {
	unsigned long long int n;
	scanf("%llu",&n);
	if(n <= 2){printf("1\n");}
	else{printf("%llu\n",gcd(n,sankaku(n)));}
	return 0;
}