import java.util.*; public class Main { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); while (scanner.hasNext()) { int n = scanner.nextInt(); int m = scanner.nextInt(); // 递归 System.out.println(rec(n, m)); // 动态规划 // System.out.println(dp(n, m)); // 组合 // System.o...