Your favourite public transport company LS (we cannot use
their real name here, so we permuted the letters) wants to
change signs on all bus stops. Some bus stops have quite a few
buses that stop there and listing all the buses takes space.
However, if for example buses 141, 142, 143 stop there, we can
write 141–143 instead and this saves space. Note that just for
two buses this does not save space.
You are given a list of buses that stop at a bus stop. What
is the shortest representation of this list?
Input
The first line of the input contains one integer
$N, 1\leq N\leq 1\, 000$,
the number of buses that stop at a bus stop. Then next line
contains a list of $N$
space separated integers between 1 and $1\, 000$, which denote the bus
numbers. All numbers are distinct.
Output
Print the shortest representation of the list of bus
numbers. Use the format as in the example, separate numbers
with single spaces and output them in sorted order.
Sample Input 1 
Sample Output 1 
6
180 141 174 143 142 175

141143 174 175 180
