/* 2. ´ÙÀ½ ÇÁ·Î±×·¥ÀÇ Ãâ·ÂÀ» ½á¶ó. */


#include <stdio.h>

int foo(int x)
{
	int y = x / 2;
	if (y == 0) return 0;
	return x + foo(y);
}

main()
{
	printf("answer = %d\n",foo(10));
}