T = int(input())
for i in range(T) :
    A = [int(s) for s in input()]
    while len(A) > 1 :
        B = A[:-1]
        for j in range(1,len(A)) :
            B[j-1] += A[j]
            if B[j-1] >= 10 :
                B[j-1] = 1 + B[j-1] % 10
        A = B
    print(A[0])