Coming off their win over the Vikings, the Broncos traveled to the O.co Coliseum to face their AFC West division rivals, the Oakland Raiders. Broncos' defensive tackle Sylvester Williams blocked a 38-yard field goal attempt by Raiders' placekicker Sebastian Janikowski late in the first quarter. The Broncos then marched down to as far as the Raiders' 8-yard line, but had to settle for a 25-yard field goal by placekicker Brandon McManus early in the second quarter. The Raiders then took a 7-3 lead, with fullback Marcel Reece receiving a 3-yard touchdown pass from quarterback Derek Carr. The Broncos were attempting to take the lead just before halftime, however, quarterback Peyton Manning was intercepted by Raiders' safety Charles Woodson in the end zone. The Broncos' offense went three-and-out on the initial possession of the second half, and on the Raiders' first play from scrimmage, Broncos' linebacker Von Miller forced a strip sack and fumble recovery of Carr deep in Raiders' territory. The Broncos had to settle for a 20-yard field goal by McManus to pull to within 7-6. Following a Raiders' three-and-out, the Broncos re-claimed the lead, with a 52-yard field goal by McManus. Following another Woodson interception of Manning, the Raiders were attempting to take the lead on the first play of the fourth quarter, however, Janikowski missed wide-left on a 40-yard field goal attempt. Trailing 9-7, the Raiders were once again attempting to take lead, until Broncos' cornerback Chris Harris, Jr. stepped in front of an errant Carr pass and returned an interception 74 yards for a touchdown. With 6:14 remaining in the game, the Raiders were in punt formation with a 4th-and-6 at their own 24-yard line. However, a 5-yard neutral zone penalty on Broncos' safety Omar Bolden gave the Raiders a 4th-and-1, and after a successful fourth-down conversion, the Raiders kept the drive alive. With 2:38 remaining in the game, the Broncos' defense denied a 4th-and-long pass completion from Carr to Reece near midfield. However, the Broncos were unable to earn a game-clinching first down just before the two-minute warning, which forced the Raiders to burn two of their three team timeouts. On the very next play, a defensive pass interference penalty on Broncos' cornerback Bradley Roby while defending a pass from Carr to wide receiver Amari Cooper moved the football to the Broncos' 32-yard line. With only one timeout remaining, the Raiders decided to send Janikowski onto the field for a 50-yard field goal to pull the Raiders to within 16-10 with 1:45 remaining in the game. The Raiders' onside kick attempt was unsuccessful, and were forced to use their last timeout on the Broncos' first play from scrimmage. Running back C. J. Anderson gained only two yards on three running plays. With eight seconds remaining, Cooper received a punt near the goal line, but the Broncos' defensive special teams subdued the Raiders' last desperation play of the game. The Broncos earned their eighth consecutive win over the Raiders, the Broncos' longest winning streak over the Raiders in franchise history, a streak that the Raiders would snap later in the season, during the teams' Week 14 rematch in Denver.

Based on the above article, answer a question. How many of Janikowski's field goals were unsuccessful?
2