#!/bin/bash

for i in 1 2 3 4 5 6 7 8 9 0 a b c d e f g h i j k l m n o p q r s t u v w x y z ; do
   mkdir $i
   chmod 777 $i
   cd $i
   for j in 1 2 3 4 5 6 7 8 9 0 a b c d e f g h i j k l m n o p q r s t u v w x y z ; do
      mkdir $j ; chmod 777 $j; echo "Processing $i/$j"
   done
   cd ..
done