#include <hall.h>

int solve(int n, int K, int s)
{
	int i, t = 0, mn = 0, p = -1;
	for(i = 0; i < n; i++)
	{
		t += 2 * ((s >> i) & 1) - 1;
		if(t < mn)
		{
			mn = t;
			p = i;
		}
	}
	return s ^ (1 << (p + 1));
}

implementer.cpp: In function ‘int main()’:
implementer.cpp:37:14: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   37 |         scanf("%d %d",&n,&K); assert(1<=n&&n<=27&&2*K>n);
      |         ~~~~~^~~~~~~~~~~~~~~
answer.code:1:10: fatal error: hall.h: No such file or directory
    1 | #include <hall.h>
      |          ^~~~~~~~
compilation terminated.