#817. Number of different words
How many different words are in the sentence? (Use a set.)
### Input
One line.
### Output
A number.
Examples
Input
robot rocket teacher planet banana rocket python
Output
6
Input
robot rocket planet scratch banana planet
Output
5
💡 You can solve it with Python, JavaScript or blocks. Read the input line by line with input(). Don't print a question (like input("Number: ")). Print exactly what the output asks for, nothing more.