You are given $n$ string $S_1, S_2,...,S_n$.
Find the shortest string $S$ that $S_1, S_2,...,S_n$ are substrings of $S$.
### Input
- The first line contains an integer $n$.
- The next $n$ lines, each line contains a string $S_i$.
### Output
- Print the shortest string.
### Constraints
- $1 \le n \le 50$.
- $1 \le |S_i| \le 10$.
### Example
Input:
```
3
ab
bcc
da
```
Output:
```
dabcc
```
### Scoring
- All test cases are scored equally.
- Consider the jury's string length as $Y$ and your string length as $X$.
- If $X \le Y$, you receive a score of $100\%$ for test case.
- If $1 < \frac{X}{Y} \le 1.5$, your score for the test case is calculated as $(\frac{3Y - 2X}{Y})^3\times 100 \\%$ .
- If $\frac{X}{Y} > 1.5$, you receive a score of $0\%$ for the test case.