diff --git a/legacy/main-old.cc b/legacy/main-old.cc
deleted file mode 100644
index 93d475c..0000000
--- a/legacy/main-old.cc
+++ /dev/null
@@ -1,30 +0,0 @@
-#include <cstdio>
-
-/*
-
-  x1 (%4) => 0 1 2 3
-  x3 (%4) => 0 3 2 1
-
-*/
-
-int main() {
-    printf("Klotski engine\n");
-
-    // 0x4FEA13400
-    //  # # # @  |  011 011 011 010 => 0100 1101 1011 -> 4DB
-    //  * * & @  |  100 111 010 111 => 1110 1011 1100 -> EBC
-    //  * * & $  |  111 111 111 010 => 0101 1111 1111 -> 5FF
-    //  . + + $  |  000 001 111 111 => 1111 1100 1000 -> FC8
-    //  . # ~ ~  |  000 011 001 111 => 1110 0101 1000 -> E58
-    // 0x0E58FC85FFEBC4DB
-
-    // 0x1A9BF0C00
-    //  @ * * @  |  010 100 111 010 => 0101 1110 0010 -> 5E2
-    //  @ * * @  |  111 111 111 111 => 1111 1111 1111 -> FFF
-    //  $ ~ ~ $  |  010 001 111 010 => 0101 1100 1010 -> 5CA
-    //  $ # # $  |  111 011 011 111 => 1110 1101 1111 -> EDF
-    //  # . . #  |  011 000 000 011 => 0110 0000 0011 -> 603
-    // 0x0603EDF5CAFFF5E2
-
-    return 0;
-}