#include <stdio.h>
#include <stdlib.h>

int read_print_median(size_t size);
int read_values(long double* values, size_t size);
int comp(const void* const a, const void* const b);
void print_array(long double values[], size_t size);

int main()
{
	int result = 0;
	size_t size = 0;
	while ( scanf("%zu", &size) != EOF )
		if ( (result = read_print_median(size)) != 0 )
			return result;

	return result;
}


int read_print_median(size_t size)
{
	if ( size == 0 )
		return 1;

	// Create an array of long doubles allocated on dynamic memory
	long double* const values = (long double*)malloc(size * sizeof(long double));
	if ( values == NULL )
	{
		fprintf(stderr, "median: error: not enough memory\n");
		return 2;
	}

	// Read values from stdin, test they were read successfully
	int result = read_values(values, size);
	if ( result != 0 )
		return result;

	// Sort values
	qsort(values, size, sizeof(long double), comp);

  #if defined(DEBUG)
	print_array(values, size);
	putchar('\n');
  #endif

	long double median = 0.0;
	if ( size % 2 == 0 )
		median = (values[size / 2 - 1] + values[size / 2]) / 2.0;
	else
		median = values[size / 2];

	printf("%Lg\n", median);
	free(values);

	return 0;
}

int read_values(long double* values, size_t size)
{
	for ( size_t index = 0; index < size; ++index )
		if ( scanf("%Lg", values + index /*&values[index]*/) != 1 )
			return 3;

	return 0;
}

int comp(const void* const a, const void* const b)
{
	// const long double* a_ld = (const long double*)a;
	return *(const long double*)a - *(const long double*)b;
}

void print_array(long double values[], size_t size)
{
	for ( size_t index = 0; index < size; ++index )
		printf("%zu: %Lg\n", index, values[index]);
}