n = int(input())
for i in range(n):
    s = list(map(int,list(input())))
    while len(s)>1:
        s_c = s.copy()
        for i in range(0,len(s)-1):
            s[i] = sum(map(int,list(str(s_c[i]+s_c[i+1]))))
        s = s[:len(s)-1]
    print(s[0])