import std.stdio,
       std.conv,
       std.string,
       std.range,
       std.math,
       std.bigint,
       std.algorithm;

void main()
{
    auto N = readln.strip.to!int;
    auto A = readln.split.to!(real[]);

    (A.sort.length % 2 ? A[$ / 2] : (A[$ / 2] + A[$ / 2 - 1]) / 2).writeln;
}