int dectobin(int n)
{
	if (n == 1) return 1;
	else return dectobin(n / 2) * 10 + n % 2;
}
int main()
{
	int n;
	printf("Enter n: ");
	scanf("%d", &n);
	printf("dectobin(n) = %d", dectobin(n));
	return 0;
}