Common Words

Given two strings s0 and s1, each representing a sentence, return the number of unique words that are shared between the two sentences.

Note: words are case-insensitive so “hello” and “Hello” are the same word.

Constraints

• n ≤ 100,000 where n is the length of s0
• m ≤ 100,000 where m is the length of s1

https://binarysearch.com/problems/Common-Words

Examples

Example 1

Input

• s0 = hello world hello oyster
• s1 = world is your oyster

Output

• answer = 2

Explanation

Only “world” and “oyster” are shared between the two sentences.

Solution