You are given an integer limit and a 2D array queries of size n x 2. There are limit + 1 balls with distinct labels in the range [0, limit]. Initially, all balls are uncolored. For every query in queries that is of the form [x, y], you mark ball x with the color y. After each query, you need to find the number of colors among the balls. Return an array result of length n, where result[i] denotes the number of colors after ith query. Note that when answering a query, lack of a color will not be considered as a color.