using namespace std;	
int a[10001],tail,s,head;
int main() {
	int n;
	cin>>n;
	for(int i=1;i<=n;i++){
		a[tail]=i;
		tail++;
	}
	while(head<tail-1){
		++s;
		if(s==3){
			head++;
			s=0;
		}
		else{
			a[tail]=a[head];
			tail++;
			head++;
		}
	}
	cout<<a[head];
	return 0;
}