Michael is trying to drive a bus from his home, (0,0) to school, located at (6,6). There are horizontal and vertical roads at every line x=0,1, \ldots, 6 and y=0,1, \ldots, 6. The city has placed 6 roadblocks on lattice point intersections (x, y) with 0 \leq x, y \leq 6. Michael notes that the only path he can take that only goes up and to the right is directly up from (0,0) to (0,6), and then right to (6,6). How many sets of 6 locations could the city have blocked?