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

int main(){
	auto N = readln.strip.to!(int);
	auto A = readln.strip.split.to!(real[]).sort!("a<b");
	writeln(N%2 == 0 ? (A[N/2-1] + A[N/2])/2 : A[(N/2).to!int]);
	return 0;
}