import sys

sys.setrecursionlimit(10**3 * 2)

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def solve():
    T = int(input())
    for test in range(T):
        S = [int(i) for i in input()]
        # debug(S, locals())
        ans = uranai(S)
        print(ans)

def uranai(S):
    if len(S) == 1:
        return S[0]
    else:
        S = [S[i] + S[i + 1] for i in range(len(S) - 1)]
        for i in range(len(S)):
            if S[i] >= 10:
                S[i] = 1 + S[i] % 10
        return uranai(S)

if __name__ == '__main__':
    solve()