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
vaibhavcs99:
20171231 08:16:40
AC after two TLE (I was using pow function).Modular exponention does the work.No need to consider when one of them is 0 cases. 

jaykay12:
20171230 20:57:42
Check


mayank1208_:
20171230 10:54:11
solved after 5 WA.but got AC in d end.... 

sgarg367:
20171203 19:07:48


justinegeo96:
20171125 13:50:18
should i check for negative values for a and b? Why am I getting WA :/ I am getting correct output using fast modular exponentiation. 

captaindavinci:
20171118 12:57:07
In this problem you could solve it by calculating (a ^ b) % 10, using fast modular exponentiation. Time complexity would be O(logb) 

sinersnvrsleep:
20171106 20:24:59
there occurs a pattern in the power of digits one needs to find that and its done 

sandilya1599:
20170927 08:12:53
python is love


mahilewets:
20170828 20:16:47
Very funny


mahilewets:
20170828 20:12:55
Python does the job 
Added by:  Jose Daniel Rodriguez Morales 
Date:  20081201 
Time limit:  1s 
Source limit:  700B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: GOSU 
Resource:  Own 