#1**0 **

Since we're dividing by 5, we need only to look at the last digit.

The last digit for each odd power of 19 is 9 -- when divided by 5, gives a remainder of 4.

The last digit for each even power of 19 is 1 -- when divided by 5, gives a remainder of 1.

geno3141 May 12, 2020