https://www.acmicpc.net/problem/1009
난이도 - 브론즈 2
알고리즘 분류 - 수학, 구현
import sys
input = sys.stdin.readline
t = int(input())
for _ in range(T):
a, b = map(int, input().split())
aa = a % 10
if aa == 0:
print(10)
elif aa in [1, 5, 6]:
print(aa)
elif aa in [4, 9]:
bb = b%2
if bb == 0:
print(aa * aa % 10)
else:
print(aa)
else:
bb = b % 4
if bb == 0:
print(aa ** 4 % 10)
else:
print(aa ** bb % 10)