题解 | #N的阶乘#

def factorial(n):  
    """计算n的阶乘"""  
    if n == 0 or n == 1:  
        return 1  
    else:  
        return n * factorial(n - 1)  
  
# 读取多组输入，直到没有输入为止  
try:  
    while True:  
        n = int(input())  
        print(factorial(n))  
except EOFError:  
    pass  # 当没有更多输入时退出循环