BelkaCTF #6: Bogus Bill

BelkaCTF #6 is over, the gang of money forgers is all caught. Thank you for being a part of this! Congratulations to the winners:
Student track: its5Q, belkakaka, kiwi
Professional track: sinsa, sm233, teo4n6

đź“„ BelkaCTF #6: Bogus Bill write-up

The Chief let out an irritated puff of air, slouching halfway towards me.

—What the heck, why didn't you just tell me straight up?

—My bad, Chief, but…

—But what?

—Well, now I'm positive these guys are not your average small fry street gang. Check out the figures!

Warmup
208
April Paycheck
Solved 96 times

What is the amount of William's first take in April?

Flag:


100 100 100 127 100 208 643 40 286 357 603 438 438 315 357 579 691 829 590 50