# CJam, <s>14</s> 13 bytes

 r$r$.{-Y/}0-!

[Try it online!][1] or [verify all test cases at once][2].

[1]: http://cjam.tryitonline.net/#code=ciRyJC57LVkvfTAtIQ&input=RUxLTlNEVVVVRUxTS0pGRVNEIERLSkVMS05TVUVMU0RVRkVVUw
[2]: http://cjam.tryitonline.net/#code=MjV7ciRyJC57LVkvfTAtIX0q&input=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