import math

def add(x, y):
    z = x + y
    if z >= 10:
        return z % 10 + z // 10
    else:
        return z

def shrink(x):
    if len(x) == 1:
        return x[0]
    else:
        r = [add(x[i], x[i+1]) for i in range(len(x)-1)]
        return shrink(r)

T = int(input())
S = [[int (j) for j in list(str(int(input())))] for i in range(T)]
for s in S:
    print(shrink(s))