T=int(input())
for tests in range(T):
    N=int(input())

    if N==0:
        print(2)
        continue

    ANS=0
    now=1
    x=N%10

    for i in range(20):
        ANS+=now
        now*=x
        x-=1

        now%=10
        x%=10

    print(ANS%10)