2025 05 `17

# def f(n):

# if n==0:

# return n

# return f(n//10)+n%10

# n=int(input())

# print(f(n))

# def f(n):

# if n-1<=0:

# return n

# return f(n-1)+f(n-2)

# n=int(input())

# print(f(n))

# n=int(input())

# def f(n):

# print(n)

# if n==1:

# return

# if n%2==1:

# f(n*3+1)

# else:

# f(n//2)

# f(n)