这道题打表
打表部分被注释了
n4 = [0,0,282, 2008, 10147, 40176, 132724, 381424, 981541, 2309384]
n3 = [0,0,21, 55, 120, 231, 406, 666, 1035, 1540]
n2 = [0,0,3, 4, 5, 6, 7, 8, 9, 10]
l,n = map(int,input().split())
if n == 2:
print(n2[l])
elif n == 3:
print(n3[l])
elif n == 4:
print(n4[l])
# ==========================
#当n == 2时：
# def f():
# ans = [0,0]
# for l in range(2,10):
# cnt = 0
# for a in range(0,min(l,9) + 1):
# if l - a >= 0:
# cnt += 1
# ans.append(cnt)
# return ans
#n2 = f()
# ==========================
#当n == 3时：
# def f():
# ans = [0,0]
# for l in range(2,10):
# cnt = 0
# for a in range(0,min(l,9) + 1):
# for b in range(0,min(l,9) + 1):
# for c in range(0,min(l,9) + 1):
# for d in range(0,min(l,9) + 1):
# if l - (a + b) >= 0 and l - (c + d) >= 0 and l - (a + c) >= 0 and l - (b + d) >= 0 and l - (2 * l - a - b - c - d) >= 0:
# cnt += 1
# ans.append(cnt)
# return ans
#n3 = f()
# ==========================
#当n == 4时：
# def f():
# ans = [0,0]
# for l in range(2,10):
# cnt = 0
# for a in range(0,min(l,9) + 1):
# for b in range(0,min(l,9) + 1):
# for c in range(0,min(l,9) + 1):
# for d in range(0,min(l,9) + 1):
# for e in range(0,min(l,9) + 1):
# for f in range(0,min(l,9) + 1):
# for g in range(0,min(l,9) + 1):
# for h in range(0,min(l,9) + 1):
# for i in range(0,min(l,9) + 1):
# if l - (a + b + c) >= 0 and l - (d + e + f) >= 0 and l - (g + h + i) >= 0 and l - (a + d + g) >= 0 and l - (b + e + h) >= 0 and l - (c + f + i) >= 0 and l - (3 * l - a - b - c - d - e - f - g - h - i) >= 0:
# cnt += 1
# ans.append(cnt)
# return ans
#n4 = f()
# ==========================