Paul and his Robots

Paul owns a factory. There are N robots working at the factory. The robots are numbered 0 to N-1. Today, exactly one of the robots got corrupted. Paul has decided to give all robots a test that may tell the number of the corrupted robot. The test works as follows: For each i from 0 to N-1, Paul tells the robot i a positive integer and the robot answers whether the integer is odd or even. Each nor