diff --git a/README.md b/README.md
index 529d005..4c5ef39 100644
--- a/README.md
+++ b/README.md
@@ -2,9 +2,16 @@
 
 "International Obfuscated Python Code Competition" and other codes...
 
-
-# palindrome
+## palindrome
 
 _yp.py_ is a source code which has the property of outputs its own source code reversed
 which you can execute again to obtain the same code.
 
+
+## iopcc 2023
+
+My submission to iopcc 2023. This source code compute fibonacci numbers by giving script
+the range of the month.
+
+Plus, source code has been tweaked to be seen as a rabbit in ASCII art.
+
diff --git a/iopcc_2023/fibonacci.py b/iopcc_2023/fibonacci.py
new file mode 100644
index 0000000..04bbef2
--- /dev/null
+++ b/iopcc_2023/fibonacci.py
@@ -0,0 +1,42 @@
+x,y=[6            ,11]\
+,[  48,67           ];s\
+ =[   x for         x   \
+ in    vars          (  )]\
+  ;b=    vars(      )[s[  x[
+   0]]]   ;k=      list(  (b.
+      __dict__      .keys  (
+      ) )) ;g=      getattr(b
+            ,k[x[1]*2]);m=g(
+            b,k[y[1]+1]);l=g\
+            (b              ,k
+            [x              [1
+          ]*        3]    ); i=\
+          g(        b,    k[  x[
+            1]        *6]);p   =g\
+            (b        ,k[y[0    ]-
+              x[0]])  ;a=g(g(b,k
+              [x[0]]  )("".join(
+              m(    g(b,k[      x[
+              0]    //2+x[      1]
+              ])    ,(m(          g(
+              b,    k[y[          0]
+              -1    ])  ,g(b,k[x  [1]+
+              y[    1]  +1])([*[  g(b,
+            k[        y[0]-1])  (y)]  *3
+            ],        [0,x[0],  0]))  ))
+          ))  ,"".            join(m(g(b
+          ,k  [x[0            ]//2+x[1]]
+        ),      (m                  (g
+        (b      ,k                  [y
+        [0        ]-                1]
+        ),        g(                b,
+    k[x[1]      +y[1              ]+1]
+    )([*[g      (b,k              [y[0
+  ]-    1])(      y)  ]*4],[x[0]*-  3,-1
+  ,x    [0]*      -2  ,x[0]//2])))  )));
+p(i((1/5**.5)*(((1+5**.5)/2)**(i(a[1])+1)-((1
+-5**.5)/2)**(i(a[1])+1)))) if l(a)>1 else p(1)
+
+# Rabbits are great to compute fibonnacci numbers
+# ASCII art freely inspired from Row - https://www.asciiart.eu/animals/rabbits
+# (c) 2023 Mindiell
diff --git a/iopcc_2023/remarks.md b/iopcc_2023/remarks.md
new file mode 100644
index 0000000..15f676d
--- /dev/null
+++ b/iopcc_2023/remarks.md
@@ -0,0 +1,36 @@
+# Remarks
+
+This source code returns the fibonacci number at the end of the nth month as explained
+on wikipedia : https://en.wikipedia.org/wiki/Fibonacci_sequence
+
+When used without any argument, it works like month 0.
+
+As stated in the source code: "Rabbits are great to compute fibonnacci numbers"
+
+## Author
+
+Mindiell (iopcc@mindiell.net)
+
+### Help and acknowledgments
+
+Thanks to AFPy and especially to mdk and entwanne for their help.
+Thanks to Row for its original ASCII art of a delicious rabbit.
+
+## Usage
+
+    python fibonacci.py N
+
+Where N is the month. It returns corresponding fibonacci number.
+
+## Compatibility
+
+No external library is necessary to run it.
+
+### Python versions
+
+It should work on python 3.10 and 3.11 only.
+
+### OS
+
+It has been succesfully launched on Debian and WSL Debian.
+