import std.algorithm, std.container, std.conv, std.math, std.range, std.typecons, std.stdio, std.string;

auto rdsp(){return readln.splitter;}
void pick(R,T)(ref R r,ref T t){t=r.front.to!T;r.popFront;}
void readV(T...)(ref T t){auto r=rdsp;foreach(ref v;t)pick(r,v);}
void readA(T)(size_t n,ref T[]t){t=new T[](n);auto r=rdsp;foreach(ref v;t)pick(r,v);}

void main()
{
  int n; readV(n);
  int[] a; readA(n, a);

  auto c = new int[](10^^5+1);
  foreach (ai; a) c[ai]++;

  auto c1 = 0, c2 = 0;
  foreach (ci; c)
    if (ci%2 == 1) ++c1;
    else if (ci > 0) ++c2;

  writeln(c1+c2-c2%2);
}
