def f(L):
    s = ''
    items = list(L)
    while items:
        first = items.pop(0)
        if isinstance(first, str):
            s += first
        else:
            items[:0] = first       
    return s
print(f(('a', ('b', ('c', ('d', 'e'))))))

def f(a: int = 2, b: int = 2) -> int:
    return a ** b
print(f(3))

f = (lambda х, у: х if х < у else у)
z1 = f('b', 'а')
z2 = f('а', 'b')
print(z1 == z2)

def f(a: int = 5, b: int = 3, c: int = 4) -> int:
    return a + b + c
print(f(2.5, b=2))

import sys
f = lambda x: list(map(sys.stdout.write, x)) 
t = f(['1', '2', '3'])

def f(a: int = '1', b: int = '2', c: int = '3') -> int:
    return a + b + c
print(f())

((lambda x: (lambda y:  x ** y)) (3)) (2)

def f(a: 1 = 2) -> 3:
    return 4
print(f())

def f(a: int = float) -> bool:
    return str
print(f())