Word Merging

Problem Description

xyq has $n$ words and wants to turn them into a single sentence.

Concretely, he merges the words two at a time, from left to right. When merging two words, find the largest $i \ge 0$ such that the length-$i$ suffix of the first word equals the length-$i$ prefix of the second word, then append the part of the second word after position $i$ to the end of the first word.

Output the final merged word.

Input Format

The first line contains an integer $n$ ($n \le 10^5$), the number of words.

The next line contains $n$ strings $s$, separated by spaces, representing the words. The total length of all strings is guaranteed not to exceed $10^6$.

Output Format

One line containing a single string: the merged answer.

Sample Input

5
sample please ease in out

Sample Output

sampleaseinout