Context: The Browns headed to New York to take on the Buffalo Bills for their Week 14 duel. It was a low-scoring affair due to the freezing rain pelting the field for much of the game. On their opening drive, the Browns drove down to the Bills' one-yard line but could not get into the end. Kicker Phil Dawson kicked a 19-yard field goal in the first quarter. In the second quarter, Ryan Fitzpatrick connected with David Nelson on an 11-yard pass for the game's only touchdown, giving the Bills a 7-3 lead. Dawson hit another field goal to pull the Browns within one, but a Rian Lindell 30-yard field goal gave the Bills a 10-6 lead at the half. Several turnovers in the second half stopped the Browns from making progress down the field, and another Lindell field goal in the fourth quarter sent the Browns to a 13-6 loss. The lone high point for the Browns was Peyton Hillis, who became the first white running back to rush for over 1,000 yards in a season in 25 years. With the loss, the Browns fell to 5-8 and were eliminated from playoff contention. This marks the eighth consecutive season in which the Browns failed to make the playoffs, a franchise record.

Question: How many points did Buffalo lead by at halftime?

Answer:
4