def solve(S):
    slst = [ord(c) - ord('0') for c in S]

    while len(slst) > 1:
        nextlst = []
        for i in range(len(slst) - 1):
            sn = slst[i] + slst[i + 1]
            if (sn >= 10):
                sn = sn % 10 + (sn // 10) % 10
            nextlst += [sn]
        #print(nextlst)
        slst = nextlst

    print(slst[0])



T = int(input())
for i in range(T):
    S = input()
    solve(S)