OjnwNb - Online Python3 Interpreter & Debugging Tool

import math
def ip():
    return map(int,input().split())
def f(x):

    lst=[]

    i=1
    while True:
        if x>=(10**i):
            lst.append(x//(10**i-1))
            i+=1
        else:
            break

    if len(lst)==0:
        return 0

    n=len(lst)
    sm=lst[-1]*n
    for i in range(n-2,-1,-1):
        lst[i]-=sm
        sm+=lst[i]*(i+1)

    ct=0
    for i in range(n):
        ct+=(i+1)*lst[i]

    return ct


T=int(input())
# T=1
for __ in range(T):
    l,r=ip()
    print(r-l+f(r-1)-f(l-1))