Cars queue on two streets at an intersection and one crosses per second, with priority to the street that crossed in the previous second. Return the time each car crosses.

Cars arrive at the intersection of two one-way streets, MAIN STREET (0) and FIRST STREET (1). You are given each car's arrival time and its street, for up to 100,000 cars, with arrival times up to 10^9 in non-decreasing order. One car crosses per second. If a FIRST STREET car crossed in the previous second, the first waiting FIRST STREET car goes next. If a MAIN STREET car crossed in the previous second, the first waiting MAIN STREET car goes next. If no car crossed in the previous second, the first waiting FIRST STREET car goes. Return the time at which each car crosses.