#468. How many times does the digit 4 appear?
You get a positive integer n. Use `while` to count how many times the digit 4 appears in it.
### Input
One integer n (1 ≤ n ≤ 10¹⁸).
### Output
One integer.
Examples
Input
144336588861339136
Output
2
Input
371960094167847955
Output
2
💡 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.