diff --git a/episodes/files/Snakefile_iterative b/episodes/files/Snakefile_iterative
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+#
+# Iterative example.
+#
+NAMES=['one','two','three']
+#
+rule done:
+  input: expand('{name}.out',name=NAMES)
+  output: 'done.out'
+  shell: 'echo "Done!" > done.out'
+rule iterate:
+  input: 
+  output: '{sample}.out' 
+  shell: 'echo {output} > {output}'