Fixing the bug where the signed integer is overflowing by using BigInteger
Merge pull request #5 from nallagsoc/1.12

Fixing the bug where the signed integer is overflowing by using BigInteg...
Revert "Merge pull request #5 from nallagsoc/1.12"

This reverts commit b8aa309328d1b59d728e4667e95c1b91d83c33c4, reversing
changes made to 5f1978701a34d3da232b92df9bd5bd17f168b615.
Merge branch '1.12'