def f(x: int, y: int) -> int:
    res = x + y
    if res >= 10:
        res = res % 10 + res // 10
    return res


def main():
    t = int(input())
    for _ in range(t):
        arr = list(map(int, list(input())))
        while len(arr) > 1:
            tmp = [f(arr[i], arr[i + 1]) for i in range(len(arr) - 1)]
            arr = tmp
        print(arr[0])


if __name__ == "__main__":
    main()