2 3 2 0 0 0 1 0 0 1 1 5 3 0 0 0 1 0 0 0 1 0 2 2 3 3 3
2 1 3 2 Hint In the first case, RD can shoot the second ball at first and hit the third ball indirectly. In the second case, RD can shoot the second or the third ball initially and hit the fourth ball as well as the fifth ball. Two schemes are both the best.