#include <stdio.h>
#include <iostream.h>

int main () { 
	
	unsigned long i, a, b, min;
	
	cin >> a;
	
	min = a*a+2*a+2;
	
	for ( i=2*a; i>a; i-- ) {
		
		if ( (a*a+1)%(i-a) == 0 ) {
			
			b = i+a+(a*a+1)/(i-a);
			if ( b < min ) min = b;
			else break;
		}
	}

	cout << min << endl;
	
	return 0;
}