Coming off their bye week, the Chargers went home, donned their throwback uniforms, and played a Week 6 AFL Legacy duel with the Denver Broncos on Monday night.  In the first quarter, San Diego struck first with kicker Nate Kaeding getting a 20-yard field goal.  The Broncos would immediately respond as wide receiver Eddie Royal returned a kickoff 93 yards for a touchdown, yet the Chargers came back with quarterback Philip Rivers completing a 3-yard touchdown pass to wide receiver Vincent Jackson.  Denver would take the lead in the second quarter with a 34-yard field goal from kicker Matt Prater and Royal returning a punt 71 yards for a touchdown.  Afterwards, San Diego closed out the half with a Kaeding 44-yard field goal and running back Darren Sproles' 77-yard punt return for a touchdown. In the third quarter, the Chargers would add onto their lead with Kaeding nailing a 50-yard field goal.  However, the Broncos would take the lead with quarterback Kyle Orton's 19-yard touchdown pass to tight end Tony Scheffler.  In the fourth quarter, Denver would increase their lead with Prater's 29-yard field goal and Orton finding wide receiver Brandon Stokley on a 5-yard touchdown pass.  San Diego tried to rally, but the Broncos' defense stood strong and held for the win. With the loss, the Chargers fell to 2-3.  This is also their 3rd straight season where after 5 games, the team has started 2-3.
Question: How many yards was the shortest field goal?
Answer: 20