n=int(input())
for i in range(n):
    s=input()
    while len(s)!=1:
        tmp=""
        for i in range(len(s)-1):
            now=int(s[i])-0+int(s[i+1])-0
            k=0
            if now>=10:
                k=now//10 + now%10
            else:
                k=now
            tmp+=str(k)
        s=tmp
print(s)