4 is COSMIC.
5 is 4, and 4 is COSMIC.
3 is 5, 5 is 4, and 4 is COSMIC.
21 is 9, 9 is 4, and 4 is COSMIC.
3000 is 13, 13 is 8, 8 is 5, 5 is 4, and 4 is COSMIC.
400 is 11, 11 is 6, 6 is 3, 3 is 5, 5 is 4, and 4 is, you guessed it, COSMIC.
I could go on and on, but those should be enough hints.
DECIPHER IT.
5 is 4, and 4 is COSMIC.
3 is 5, 5 is 4, and 4 is COSMIC.
21 is 9, 9 is 4, and 4 is COSMIC.
3000 is 13, 13 is 8, 8 is 5, 5 is 4, and 4 is COSMIC.
400 is 11, 11 is 6, 6 is 3, 3 is 5, 5 is 4, and 4 is, you guessed it, COSMIC.
I could go on and on, but those should be enough hints.
DECIPHER IT.