"Seventy Times Seven"
by cm

Then Peter came to Jesus and asked, "Lord, how many times shall I forgive my brother when he sins against me? Up to seven times?" Jesus answered, "I tell you, not seven times, but seventy times seven."

Matthew 18: 21-22

Therefore, taking Jesus's instructions literally, the "First of the Seventy First", or the first sin of the 71st group of seven sins, is unpardonable.