#include <vector> #include <list> #include <map> #include <set> #include <deque> #include <stack> #include <queue> #include <bitset> #include <algorithm> #include <functional> #include <numeric> #include <utility> #include <sstream> #include <iostream> #include <iomanip> #include <cstdio> #include <cmath> #include <cstdlib> #include <cctype> #include <string> #include <cstring> #include <ctime> using namespace std; inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;} template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();} typedef vector<int> VI; typedef vector<VI> VVI; typedef vector<string> VS; typedef pair<int, int> PII; typedef tuple<int, int, int> TIII; typedef long long LL; typedef unsigned long long ULL; #define FOR(i,a,b) for(int i=(a);i<(b);++i) #define REP(i,n) FOR(i,0,n) #define MP make_pair #define MT make_tuple #define SZ(a) int((a).size()) #define EACH(i,c) for(auto i: c) #define SORT(c) sort((c).begin(),(c).end()) #define ALL(a) (a).begin(),(a).end() #define RALL(a) (a).rbegin(), (a).rend() const double EPS = 1e-10; const double PI = acos(-1.0); #define dump(x) cerr << #x << " = " << (x) << endl; #define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl; int main() { cin.tie(0); ios::sync_with_stdio(false); int N; cin >> N; VI A(N); REP(i, N) cin >> A[i]; SORT(A); double ret; if(N % 2 == 0){ ret = 1.0 * (A[N / 2 - 1] + A[N / 2]) / 2; } else{ ret = A[N / 2]; } cout << ret << endl; return 0; }