#430. How many times does the digit 1 appear?
You get a positive integer n. Use `while` to count how many times the digit 1 appears in it.
### Input
One integer n (1 ≤ n ≤ 10¹⁸).
### Output
One integer.
Examples
Input
552978441663515398
Output
2
Input
863409619694241152
Output
3
💡 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.