That solution is, as you might know by now, is that the group lose their virginity together, resulting in the boys one by one having sex with Bev.
A quick rundown on what happens and why: Stephen King’s 1988 novel sees The Losers’ Club temporarily defeating Pennywise, but unable to find their way out of the sewers of Derry.
With this perilous situation at hand, Beverly Marsh suggests an action that will bring the group together, focusing their minds and helping them get out of a potential watery grave.
So the story goes, it works in sending the group on their way out of the sewer, and indicates the two men Bev could potentially wind up with in the end of IT: Bill Denborough and Ben Hascom.