Description

In a pasture, the grass grows at a constant rate every day. This pasture can feed $15$ cows for $20$ days or $20$ cows for $10$ days. How many cows can the new grass grown each day feed for $1$ day?

Input Format

None.

Output Format

Output a natural number representing how many cows the new grass grown each day can feed for $1$ day.

Sample

None

10