#include <string>#include <vector>#include <algorithm>#include <iostream>#include <sstream>#include <fstream>#include <map>#include <set>#include <cstdio>#include <cmath>#include <cstdlib>#include <ctime>#include <queue>#include <utility>#include <cstring>#include <list>#include <stack>#include <cstdio>using namespace std;#define ft first#define sd secondtypedef long long LL;typedef unsigned int UI;const int MAXN = 511111;const int MOD = 1e9 + 7;const double eps = 1e-6;const LL MAXL = (0x7fffffffffffffffLL);const int MAXI = 0x7fffffff;long long a[1111111];int partition(int l, int r) { int i = rand() % (r - l + 1) + l; swap(a[l], a[i]); int s = l, e = r; LL pivot = a[l]; while (s < e) { while (s < e && a[e] > pivot) e--; if(s < e) a[s++] = a[e]; while (s < e && a[s] < pivot) s++; if(s < e) a[e--] = a[s]; } a[s] = pivot; return s;}LL solve(int l, int r, int k) { int p = partition(l, r); if (p == k) { return a[p]; } if (k > r || k < 0) { return -1; } if (k < p) { return solve(l, p-1, k); } if (k > p) { return solve(p+1, r, k); } return 0;}int main() { int n, k; while (cin >> n) { for (int i = 1; i <= n; i++) scanf("%lld", a+i); sort(a+1, a+n+1); if(n&1) printf("%.1fn", a[(n+1)/2]*1.0); else printf("%.1fn", (a[n/2]*1.0+a[n/2+1]*1.0)/2); }}
