import std.algorithm;
import std.array;
import std.conv;
import std.stdio;
import std.string;

void main()
{
  auto s = readln.chomp;

  const a = 'Z' - 'A' + 1;

  auto r = "";
  foreach (i, c; s) {
    auto d = (c - 'A' + a - (i + 1) % a) % a + 'A';
    r ~= d.to!char;
  }

  writeln(r);
}