#495. How many times does the digit 7 appear?
You get a positive integer n. Use `while` to count how many times the digit 7 appears in it.
### Input
One integer n (1 ≤ n ≤ 10¹⁸).
### Output
One integer.
Examples
Input
545066430977958085
Output
2
Input
80093467968561409
Output
1
💡 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.