LASTDIG  The last digit
Nestor was doing the work of his math class about three days but he is tired of make operations a lot and he should deliver his task tomorrow. His math’s teacher gives him two numbers a and b. The problem consist of finding the last digit of the potency of base a and index b. Help Nestor with his problem. You are given two integer numbers: the base a (0 <= a <= 20) and the index b (0 <= b <= 2,147,483,000), a and b both are not 0. You have to find the last digit of a^{b}.
Input
The first line of input contains an integer t, the number of test cases (t <= 30). t test cases follow. For each test case will appear a and b separated by space.
Output
For each test case output an integer per line representing the result.
Example
Input: 2 3 10 6 2
Output: 9 6
hide comments
coderaashir:
20160530 14:46:39
It says 0 <= b and a so they can be equal. 

manish3749:
20160525 23:00:34
awesome one... must solve....accepted in first go 

avisheksanvas:
20160518 11:41:08
https://crypto.stanford.edu/pbc/notes/numbertheory/exp.html


vinu0103:
20160517 14:35:53
learnt a new technique modular exponentiation 

sayedathar11:
20160506 18:32:19
ac in one go number theory rocks :)


walid_salah:
20160328 21:35:22
It can be solved by quaternary numeral system ?


ianand:
20160325 14:25:36
check for 12 2351357


aru_674:
20160323 10:48:29
b can be 0 please edit!!! 

xtreampy:
20160320 19:52:35
watch out when b(power) = 0 

mhto:
20160318 16:54:15
Tried with all possible test case, works fine on ideone. But SPOJ says wrong answer.

Added by:  Jose Daniel Rodriguez Morales 
Date:  20081201 
Time limit:  0.340s 
Source limit:  700B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All 
Resource:  Own 