808888888888888888888888888888888
888888888888888888888888888888888
88888888888888881111888888118888
8888888888111111111188111888888
8888888811111188888811118888888
8888888111188888888111111888888
8888888111888888811188111188888
8888888111888888111888811188888
888888811118888888881118888888
888888811118888888881118888888
888888811118888888811118888888
8888888111811111111111188888888
8888118888811111111188888888888
88888888888888888888888888888881
is a prime with 420 digits