39: Jewels and stones

Given two strings: jewels and stones. Each character in jewels it's a unique type of jewels. stones are the stones what you have. Find out how many of your stones are jewels

 

Example 1

Input: jewels = "aBb", stones = "cBbbA"

Output: 3

Example 2

Input: jewels = "abc", stones = "ABC"

Output: 0