#include <bits/stdc++.h> 

using i64 = long long; 
using u64 = unsigned long long; 
using u32 = unsigned; 

using u128 = unsigned __int128; 
using i128 = __int128; 

void solve() {
	int N; std::cin >> N;

	std::vector<int> A(N);
	for(int& x : A) std::cin >> x;
	std::sort(A.begin(), A.end());
	
	std::cout << std::fixed << std::setprecision(1);
	if(N % 2 != 0) std::cout << A[N / 2];
	else std::cout << (1.0 * A[N / 2] + A[N / 2 - 1]) / 2;
} 

int main() { 
	std::ios::sync_with_stdio(false); 
	std::cin.tie(nullptr); 

	int T = 1; 
	//std::cin >> T; 

	while (T--) { 
		solve(); 
	} 
	return 0; 
}