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
rashmit:
20201227 09:44:38
dammn!! that 700 byte thing...i had to remove the comments XD 

dktomar9456:
20201118 14:27:32
check your code for b=0


sivan_353:
20201108 15:57:12
It is kinda tricky Last edit: 20201108 16:02:26 

dileep_32:
20201105 16:13:21
judge wont accept your solution if it takes code size > 700 bytes so watch out for that . for me it took a hell out of time to optimizzze 

Sameer Anand:
20201014 18:01:15
Guys, the value of 'b' CAN be zero in the problem. I don't know why would the asker specifically say the opposite in the problem statement. Wasted my 2 hours. 

bodo2:
20201009 02:38:04
why it is saying "Your solution is too long for this problem, the limit is 700 bytes!"


naveen1948:
20201003 13:10:30
dont directly compute a power b it will not work and will show run time error as the time required to calculate for large numbers is more


ayan_v:
20201002 06:33:20
used Euler totient function gave the right answer but the compiler not accepting 

saquelain:
20200929 06:14:25
compute mod 10 in power funtion


whiterose000:
20200922 16:09:19
I am using modular binary exponentiation in this problem but it gives me 700 bytes error and says my program is using much more space then this. please help!! 
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 