/*
Rectangular playing board with nrows and ncols.
Robot is in upper left corner, must move one square at a time
(right and down) to lower right corner.
How many possible paths?
*/

import java.util.ArrayList;
import java.util.List;

public class Robot {
	public static void main(String[] args) {
		int nrows = 3;
		int ncols = 3;

		System.out.println(numberOfPaths(nrows, ncols));
		System.exit(0);
	}

	private static int numberOfPaths(int nrows, int ncols) {
		assert nrows >= 1 && ncols >= 1;

		if (nrows == 1 || ncols == 1) {
			return 1;
		}
		return numberOfPaths(nrows - 1, ncols) + numberOfPaths(nrows, ncols - 1);
	}
}