Total number of unique characters

Problem to count the unique characters given two strings.

Example-1:

Input    : s1 = "my"  s2 = "crazy"  
Output   : 6  

Example-2:

Input    : s1 = "hello"  s2 = "world"
Output   : 7 

Solution

s1 = "my"

s2 = "crazy"

s3 = s1+s2

print(len(set(s3)))

Output

6