In recreational mathematics, a [Keith number](https://en.wikipedia.org/wiki/Keith_number) or repfigit number (short for repetitive Fibonacci-like digit) is a number in the following integer sequence:
`14, 19, 28, 47, 61, 75, 197, 742, 1104, 1537, 2208, 2580, 3684, 4788, 7385, 7647, 7909, ...` (sequence A007629 in the OEIS)
Keith numbers were introduced by Mike Keith in 1987. They are computationally very challenging to find, with only about 100 known.
Implement the code to check if the given number is a Keith number. Return the number number of iteration needed to confirm it; otherwise return `false`.
**Note:** 1-digit numbers are **not** Keith numbers by definition
## Examples
```
n = 197      # --> [1, 9, 7]
# calculation           iteration
1 + 9 + 7 = 17         #    1
9 + 7 + 17 = 33        #    2
7 + 17 + 33 = 57       #    3
17 + 33 + 57 = 107     #    4
33 + 57 + 107 = 197    #    5
```
As `197` is the same as the initial number, so it's a Keith number: return `5`
Another example:
```
n = 196
# calculation          iteration
1 + 9 + 6 = 16        #    1
...
```
`196` is not a Keith number, so return `false`
def is_keith_number(n):
    numList = [int(i) for i in str(n)]  # int array
    if len(numList) > 1:  # min 2 digits
        itr = 0
        while numList[0] <= n:
            # replace array entries by its sum:
            numList[itr % len(numList)] = sum(numList)
            itr += 1
            if n in numList:  # keith-condition
                return itr
    return False
def is_keith_number(n):
    numList = [int(i) for i in str(n)]  # int array
    if len(numList) > 1:  # min 2 digits
        itr = 0
        while numList[0] <= n:
            # replace array entries by its sum:
            numList[itr % len(numList)] = sum(numList)
            itr += 1
            if n in numList:  # keith-condition
                return itr
    return False