int unknown(int n){ 
	int i, j, k=0; 
	for (i=n/2; i<=n; i++) 
	    for (j=2; j<=n; j=j*2) 
		k = k + n/2; 
	return (k); 
}

int unknown(int n){ 
	int i, j, k=0; 
	for (i=n/2; i<=n; i++) 
	    for (j=2; j<=n; j=j*2) 
		k = k + n/2; 
	return (k); 
}