diff --git a/substitution0/message.txt b/substitution0/message.txt
new file mode 100755
index 0000000..d4a99fb
--- /dev/null
+++ b/substitution0/message.txt
@@ -0,0 +1,12 @@
+OHNFUMWSVZLXEGCPTAJDYIRKQB 
+
+Suauypcg Xuwaogf oacju, rvds o waoiu ogf jdoduxq ova, ogf hacywsd eu dsu huudxu
+mace o wxojj noju vg rsvns vd roj ugnxcjuf. Vd roj o huoydvmyx jnoaohouyj, ogf, od
+dsod dveu, yglgcrg dc godyaoxvjdj—cm ncyaju o wauod pavbu vg o jnvugdvmvn pcvgd
+cm ivur. Dsuau ruau drc acygf hxonl jpcdj guoa cgu ukdauevdq cm dsu honl, ogf o
+xcgw cgu guoa dsu cdsua. Dsu jnoxuj ruau uknuufvgwxq soaf ogf wxcjjq, rvds oxx dsu
+oppuoaognu cm hyagvjsuf wcxf. Dsu ruvwsd cm dsu vgjund roj iuaq aueoalohxu, ogf,
+dolvgw oxx dsvgwj vgdc ncgjvfuaodvcg, V ncyxf soafxq hxoeu Zypvdua mca svj cpvgvcg
+aujpundvgw vd.
+
+Dsu mxow vj: pvncNDM{5YH5717Y710G_3I0XY710G_03055505}
\ No newline at end of file
diff --git a/substitution0/sol.py b/substitution0/sol.py
new file mode 100755
index 0000000..1775f09
--- /dev/null
+++ b/substitution0/sol.py
@@ -0,0 +1,18 @@
+#!/home/maxime/.pyvenv/bin/python3
+
+key = "OHNFUMWSVZLXEGCPTAJDYIRKQB"
+
+D = {}
+for i, char in enumerate(key):
+    D[char] = chr(ord('A') + i)
+    D[char.lower()] = chr(ord('a') + i)
+
+with open("message.txt", 'r') as f:
+    for char in f.read():
+        if char in D:
+            print(D[char], end='')
+        else:
+            print(char, end='')
+
+print()
+