diff --git a/euler_ruby/.ex8.rb.swp b/euler_ruby/.ex8.rb.swp
deleted file mode 100644
index 3f2242c..0000000
Binary files a/euler_ruby/.ex8.rb.swp and /dev/null differ
diff --git a/euler_ruby/ex8.rb b/euler_ruby/ex8.rb
index c31d17e..ce4a953 100644
--- a/euler_ruby/ex8.rb
+++ b/euler_ruby/ex8.rb
@@ -1,16 +1,16 @@
 require "pry"
 NUM = "7316717653133062491922511967442657474235534919493496983520312774506326239578318016984801869478851843858615607891129494954595017379583319528532088055111254069874715852386305071569329096329522744304355766896648950445244523161731856403098711121722383113622298934233803081353362766142828064444866452387493035890729629049156044077239071381051585930796086670172427121883998797908792274921901699720888093776657273330010533678812202354218097512545405947522435258490771167055601360483958644670632441572215539753697817977846174064955149290862569321978468622482839722413756570560574902614079729686524145351004748216637048440319989000889524345065854122758866688116427171479924442928230863465674813919123162824586178664583591245665294765456828489128831426076900422421902267105562632111110937054421750694165896040807198403850962455444362981230987879927244284909188845801561660979191338754992005240636899125607176060588611646710940507754100225698315520005593572972571636269561882670428252483600823257530420752963450"
-puts "starting... with #{NUM.size}"
-
 NUM2 = NUM.split("")
+puts "starting... with #{NUM2.size}"
+return -1 if NUM.size != NUM2.size
 res = []
 puts "original size of num: #{NUM2.size}"
 until NUM2.size == 0
   puts "in the loop"
   itr = []
-  NUM2.first(4).each { |n| itr << n.to_i }
+  NUM2.first(13).each { |n| itr << n.to_i }
   res << itr.inject(:*)
-  NUM2.shift(4)
+  NUM2.shift(1)
   puts "loop done #{NUM2.size} "
 end