Coming off their divisional home win over the Giants, the Cowboys flew to Dolphin Stadium for a Week 2 interconference fight with the Miami Dolphins.  In the first quarter, Dallas trailed early with Dolphins kicker Jay Feely getting a 37-yard field goal.  The Cowboys would tie the game with rookie kicker Nick Folk getting a 26-yard field goal.  In the second quarter, Dallas took the lead with RB Marion Barber getting a 1-yard TD run.  Miami would close out the first half with Feely getting a 45-yard field goal. In the third quarter, the Cowboys trailed as Dolphins QB Trent Green completed an 18-yard TD pass to WR Marty Booker.  Dallas jumped back into the lead with QB Tony Romo completing a 2-yard TD pass to TE Tony Curtis, along with Folk's 28-yard field goal.  In the fourth quarter, the Cowboys took control with Folk's 47-yard field goal and Romo's 34-yard TD pass to WR Terrell Owens.  Miami's Green completed a 21-yard TD pass to WR Derek Hagan, but Dallas responded with Barber's 40-yard TD run. On defense, they managed to force 5 turnovers, 4 of which came from intercepting Trent Green passes.
Question: How many yards ws the longest touchdown run?
Answer: 40