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
amish1999:
20200518 15:00:57
Here we only need to calculate (a^b)mod 10 with the help of modular exponentiation. Last edit: 20200518 15:05:57 

avi_kumar15:
20200517 19:37:34
700B lol 

elucidase:
20200517 14:18:37
Euclid theorem gives cycle 4 for coprime numbers; others you can check, also with period 4. 

meher_24:
20200510 22:26:45
this little judge doesnt like pow function guys.Nothing is wrong with ur code people. 

amar_shukla1:
20200508 12:15:31
easy problem


kuldeepkarhana:
20200429 10:16:58
just use binary exponention with mod 10 that's it. 

satwikmishra1:
20200426 13:18:12
good problem,consider the cases when a or b might be 0 and yes,AVOID if else statements,check 700 bit constrains and yes please consider switching lines while printing the output. 

saddy_2001:
20200423 20:44:50
use fast exponentiation !


abhishek_251:
20200417 21:14:51
at most you have to make 4 multiplications to get the answer :) just find the pattern only. 

s_cube98:
20200221 20:29:13
The constraints made this one interesting tho!! Last edit: 20200221 22:07:23 
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 