import java.util.Scanner;

public class Demo01 {

	private int[][] matrix(int k, int l){
		int[][] matrix = new int[l][k];
		for(int i = 0; i < k; i ++){
			matrix[0][i] = 1;
		}
		matrix[0][0] = 0;
		for(int i = 1; i < l; i ++){
			for(int j = 0; j < k; j ++){
				for(int n = 0; n < k; n ++){
					if((n - j) != 1 && (j - n) != 1){
						matrix[i][j] = (matrix[i][j] + matrix[i - 1][n]) % 1000000007;
					}
				}
			}
		}
		int count = 0;
		for(int i = 0; i < k ; i ++){
			count = (count + matrix[l - 1][i]) % 1000000007;
		}
		System.out.println(count);
		return matrix;
	}
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int k = sc.nextInt();
		int l = sc.nextInt();
		new Demo01().matrix(k, l);
	}
}