Here it is in PigJava:

int n=the number, rem=the remainder;

If (n==odd) do the divisibility test of 3 for n; if (divisible) rem=3; else rem=1or5;
Then do the divisibility test of 3 for n-1; if (divisible) rem=1; else rem=5;

If (n==even) do the divisibility test of 3 for n; if (divisible) rem=0; else rem=2or4;
Then do the divisibility test of 3 for n-1; if (divisible) rem=4; else rem=2;

Best Wishes