T = int(input())

for i in range(T):
    l = list(input())
    for j in range(len(l) - 1):
        for k in range(len(l) - 1):
            new = int(l[k]) + int(l[k + 1])
            if new > 9:
                new = str(new)
                new = int(new[0]) + int(new[1])
            l[k] = new
        l.pop()
    print(l[0])