Coming off their commanding road win over the Browns, the Cowboys played their Week 2 home opener under the MNF spotlight.  In the last MNF game at Texas Stadium, Dallas would duel with their NFC East foe, the Philadelphia Eagles.  In the first quarter, the Cowboys trailed early as Eagles kicker David Akers got a 34-yard field goal.  Dallas would answer in their first possession with QB Tony Romo completing a 72-yard TD pass to WR Terrell Owens.  Philadelphia replied with Akers kicking a 44-yard field goal, yet the 'Boys immediately added to their lead with rookie RB Felix Jones returning a kickoff 98 yards for a touchdown. The Eagles would take the lead with QB Donovan McNabb completing a 6-yard TD pass to RB Brian Westbrook, along with LB Chris Gocong recovering a Romo fumble in the Cowboys' endzone for a touchdown.  Dallas immediately responded with Romo and Owens hooking up with each other again on a 4-yard TD pass. On Philadelphia's next drive, the referees made two suspect decisions. The first was a non-call on a very obvious facemask on Brian Westbrook that would have given the Eagles a first down. The next call in question was a 40-yard passing interference penalty on Anthony Henry. Replays showed that it was Greg Lewis who grabbed Henry's jersey and pulled him down, not the other way around. With that decision, the Eagles were awarded a first down on the 1-yard line. Westbrook immediately ran it in for a 1-yard TD. On their next possession, Akers' hit a 22-yard field goal. To make the game the highest scoring half ever on MNF, the Cowboys ended the half with kicker Nick Folk getting a 51-yard field goal, bringing the total points for both teams to 54. In the third quarter, the 'Boys regained the lead with Romo's 17-yard TD pass to RB Marion Barber. In the fourth quarter, the Eagles once again took the lead with Westbrook's 1-yard TD run.  Afterwards, the Cowboys rallied with Folk nailing a 47-yard field goal and Barber getting a 1-yard TD run. The Eagles had a chance for a game-winning drive, but Dallas' defense stiffened for the victory, sacking the very elusive McNabb twice. In a game that had 9 lead changes, it also set different point records, including most first half points in MNF history (54) and most combined points in the rivalry's history (78). Also, Terrell Owens (3 receptions for 89 yards and 2 touchdowns) reached 132 career touchdown catches, placing him 2nd on the NFL's all-time touchdown receptions list (behind only Jerry Rice's record of 197).
Question: How many yards was the longest field goal of the first half?
Answer: 51-yard