def simplex_number(d, n):
    # 动态规划表
    dp = [[0] * (n + 1) for _ in range(d + 1)]
    
    # 初始化一维简单形数
    for i in range(1, n + 1):
        dp[1][i] = i
    
    # 动态递推
    for dim in range(2, d + 1):
        for num in range(1, n + 1):
            dp[dim][num] = dp[dim][num - 1] + dp[dim - 1][num]
    
    return dp[d][n]

# 示例：计算五维的第 4 项
result = simplex_number(50, 50)
print(f"5D 第 4 项：{result}")