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

void readV(T...)(ref T t){auto r=readln.splitter;foreach(ref v;t){v=r.front.to!(typeof(v));r.popFront;}}

void main()
{
  string s; readV(s);
  auto n = s.length;
  auto t = new dchar[]((n+1)/2);
  foreach (i; 0..(n+1)/2) t[i] = s[i*2];
  writeln(t);
}
