The Broncos traveled to Arrowhead Stadium for an AFC West rematch with the Kansas City Chiefs.  This was a historic game as NFL Network began their season with a 3rd NFL game on Thanksgiving.  In the 1960s, Kansas City hosted three Thanksgiving Day games.  For this battle, QB Jake "The Snake" Plummer was fighting for his starting job. In the first quarter, the Broncos trailed early as K.C.'s Lawrence Tynes kicked a 24-yard field goal for the only score of the period.  In the second quarter, Denver's defensive problem continued as RB Larry Johnson got a 1-yard TD run.  The Broncos would finally score as kicker Jason Elam nailed a 31-yard field goal.  In the third quarter, Tynes helped the Chiefs get a 34-yard field goal, while Plummer completed a 1-yard TD pass to TE Stephen Alexander.  In the fourth quarter, Tynes gave Kansas City a 29-yard and a 21-yard field goal.  The Broncos tried to respond, but K.C.'s improved defense stopped any hope of a comeback.  With the loss, Denver fell to 7-4.
Question: How many yards was the shortest field goal?
Answer: 21