Implement Unix uniq

Build a lightweight version of the Unix uniq utility.

You will receive a sequence of strings — n lines total. Print them back in the same order, except that whenever the same string repeats in consecutive lines (a run), you keep only the first line of that run and drop the rest.

Key rules:

• The deduplication applies solely to adjacent duplicates. Non-consecutive occurrences of the same string are unaffected and must still appear.
• Comparisons are case‑sensitive. "Apple" and "apple" count as different strings.
• An empty string (a blank line) is a perfectly valid line and behaves like any other string.

Input Format

n
line_1
line_2
...
line_n

• 0 <= n <= 100000
• 0 <= len(line_i) <= 1000
• The total size of the input will not exceed 10 MB.

Output Format

Print the filtered lines — one per line — to standard output.

Examples

Example 1

Input:

7
apple
apple
banana
banana
banana
apple
apple

Output:

apple
banana
apple

Explanation: The first two "apple" lines form a run (only the first kept). The three "banana" lines form another run (only the first kept). The final two "apple" lines are a new run (again, only the first kept).

Example 2

Input:

5
a
A
A
a
a

Output:

a
A
a

Explanation: "a" and "A" are different because the comparison is case‑sensitive. The run "A", "A" collapses to a single "A", and the trailing "a", "a" collapses to a single "a".