Before proceeding, I want to let you know that this is not a tutorial blog. There are already plenty of well-written tutorials (including video tutorials) available out there.

Recently, I encountered a problem that could be solved using a Trie. This sparked my interest in learning the data structure to tackle that specific problem.

However, I soon realized that nearly every tutorial out there implements a Trie using pointers. Out of curiosity, I wanted to explore how to implement it without using pointers. I searched extensively online but, surprisingly, found no clear guidance.

Eventually, I decided to implement it on my own — and that’s exactly what led to the creation of this blog.

for i in range(int(input())):
    x,y=map(int,input().split())
    if x==y==1:
        print(1)
    else:
        print(y-x)