HARRISBURG, Pa. (AP) — Pennsylvania school leaders are figuring out how to use billions in federal coronavirus relief. It’s a flood of cash that can help lower class sizes, underwrite construction projects and assist children in catching up after a year and a half of pandemic-caused educational disruption. One school superintendent calls it “a game changer.” In Pennsylvania, the largest cities collected the most in federal pandemic relief money, with the 130,000-student Philadelphia public schools receiving nearly $1.8 billion. Districts are looking at ways to help kids catch up, to address their mental health needs and to make their buildings cleaner and safer, among other things.