Digits

Time limit1sMemory limit128 MB

Summary
Given a huge decimal number, repeatedly replace it with its digit count and report the first step where the value stops changing.
Level

Medium4 of 10

Topics
Math, Implementation, Simulation, String
Solved
No attempts yet

Problem

A googol written out in decimal has 101101 digits. A googolplex has one plus a googol digits. That's a lot of digits!

Given any number x0x_0, define a sequence by the recurrence

xi+1=the number of digits in the decimal representation of xi.x_{i+1} = \text{the number of digits in the decimal representation of } x_i.

Your task is to determine the smallest positive ii such that xi=xi−1x_i = x_{i-1}.

Input

The input consists of several lines. Each line contains a value of x0x_0. Every value of x0x_0 is non-negative and has no more than one million digits. The last line of input contains the word END.

Output

For each value of x0x_0 in the input, output one line containing the smallest positive ii such that xi=xi−1x_i = x_{i-1}.

Examples1

  1. Example 1

    Input
    42
    END
    
    Expected output
    3