Can somebody explayne me plz lost hope

Question

The snail climbs up 7 feet each day and slips back 2 feet each night.
How many days will it take the snail to get out of a well with the given depth?

Sample Input:
31

Sample Output:
6

Explanation: Let's break down the distance the snail covers each day:
Day 1: 7-2=5
Day 2: 5+7-2=10
Day 3: 10+7-2=15
Day 4: 15+7-2=20
Day 5: 20+7-2=25
Day 6: 25+7=32
So, on Day 6 the snail will reach 32 feet and get out of the well at day, without slipping back that night.

The task name: snail in the well :)

Answer 1

In a day snail climbs up 7 feet, if it not reach given depth (means not out of wall), then drops 2 feet. This will be repeated next days till it reached wall.. what else you not understanding?