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

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;
}

int main()
{
	unsigned long long size = 0;
	if ( scanf("%llu", &size) == EOF )
		return 0;

	long double* const values = (long double*)malloc(size * sizeof(long double));
	if ( values == NULL )
	{
		fprintf(stderr, "median: error: not enough memory\n");
		return 1;
	}

	for ( long long index = 0; index < size; ++index )
		if ( scanf("%Lg", &values[index]) == EOF )
			return 2;

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

	for ( long long index = 0; index < size; ++index )
		printf("%llu: %Lg\n", index, values[index]);

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

	return 0;
}