def cnt_digit(st):
    k = len(st)
    n = int(st)
    i = 0
    ans = 0
    while n > (m := 9 * 10**i):
        n -= m
        i += 1
        ans += i * m
    ans += (i + 1) * n
    return ans

def divide(sa, sb):
    a, b = int(sa), int(sb)
    u, v = a, b
    r = cnt_digit(sb) - cnt_digit(str(a - 1))
    step = 0
    while v - u > 1:
        step += 1
        m = (u + v) // 2
        if 2 * c > r:
            v = m
        else:
            u = m
    return u

n = int(input())
for _ in range(n):
    sa, sb = input().split()
    r = divide(sa, sb)
    print(r)