# Stair Steps

Elementary+
DE English RU

There is a staircase with N steps and two platforms; one at the beginning, the other at the end of the stairs. On each step a number is written (ranging from -100 to 100 with the exception of 0.) Zeros are written on both platforms. You start going up the stairs from the first platform, to reach the top on the second one. You can move either to the next step or to the next step plus one. You must find the best path to maximize the sum of numbers on the stairs on your way up and return the final sum.

Input: Numbers on each stair as a list of integers.

Output: The final sum for the best way as an integer.

Example:

```checkio([5, -3, -1, 2]) == 6
checkio([5, 6, -10, -7, 4]) == 8
checkio([-11, 69, 77, -51, 23, 67, 35, 27, -25, 95]) == 393
checkio([-21, -23, -69, -67, 1, 41, 97, 49, 27]) == 125```

How it is used: This is a classical example of the optimisation problem. It can show you the difference between the various methods of programming; such as dynamic programming and recursion.

Precondition:
0 < len(steps) ≤ 10
all(-100 < x < 100 and x for x in steps)

Settings
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CheckiO Extensions

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In order to install CheckiO client you'll need installed Python (version at least 3.8)

Install CheckiO Client first:

`pip3 install checkio_client`

`checkio --domain=py config --key=`

Sync solutions into your local folder

`checkio sync`

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`checkio serv -d`

Alternatevly, you can install Chrome extension or FF addon

`checkio install-plugin`
`checkio install-plugin --ff`
`checkio install-plugin --chromium`

Read more here about other functionality that the checkio client provides. Feel free to submit an issue in case of any difficulties.

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