#include <iostream>
#include <cassert>
#define llint long long

using namespace std;

llint n;

int main(void)
{
	cin >> n;
	assert(n >= 1 && n < (1LL<<60));
	
	llint ans = 1;
	for(; (ans<<1) <= n; ans<<=1);
	cout << ans << endl;
	
	return 0;
}