PROGRAMMING:Date formatting
When filling in the date in the document, different people have different writing habits. Many people are used to using the decimal point as the separator, such as "2018.10.20". In some special occasions, it needs to be written as "2018-10-20". Next, please write a program to automatically read in the decimal point division of the date rewritten with the form of -.
###Input format:
Input the year, month and day in a row in the format of "yyyy. Mm. DD". The title guarantees that the date given is the legal date since new year's Day 1900.
###Output format:
Output the date in the format of "yyyy MM DD" in one line.
###Input example:
```in
2018.03.13
```
###Output example:
```out
2018-03-13
```
answer：If there is no answer, please comment
###Input format:
Input the year, month and day in a row in the format of "yyyy. Mm. DD". The title guarantees that the date given is the legal date since new year's Day 1900.
###Output format:
Output the date in the format of "yyyy MM DD" in one line.
###Input example:
```in
2018.03.13
```
###Output example:
```out
2018-03-13
```
answer：If there is no answer, please comment