class A:
    def __init__(self, txt: str):
        self.r: F = None
        self.w: D = None
        self.t: E = None
        self.s: E = None
        self.x: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.w: E = None
        self.v: F = None
        self.s: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.q: B = None
        self.v: F = None
        self.y: C = None
        self.t: E = None
        self.r: C = None
        self.x: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: E = None
        self.t: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: A = None
        self.r: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: F = None
        self.r: F = None
        self.u: E = None
        self.t: E = None
        self.txt = txt

e = A("e")
a = B("a")
g = C("g")
i = D("i")
l = E("l")
f = F("f")
m = C("m")
c = F("c")
j = C("j")

e.r = c
e.w = i
e.t = l
e.s = l
e.x = m
a.w = l
a.v = f
a.s = g
g.q = a
g.v = f
g.x = f
g.y = j
g.r = j
g.t = l
i.w = l
i.t = a
l.t = e
l.r = e
f.s = c
f.r = c
f.u = l
f.t = l
m.q = a
m.v = f
m.y = j
m.t = l
m.r = g
m.x = c
c.s = f
c.r = f
c.u = l
c.t = l
j.q = a
j.v = c
j.y = m
j.r = m
j.t = l
j.x = f
assert f.s.r.u.r.r.u.txt == "
class A:
    def __init__(self, txt: str):
        self.r: F = None
        self.w: D = None
        self.t: E = None
        self.s: E = None
        self.x: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.w: E = None
        self.v: F = None
        self.s: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.q: B = None
        self.v: F = None
        self.y: C = None
        self.t: E = None
        self.r: C = None
        self.x: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: E = None
        self.t: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: A = None
        self.r: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: F = None
        self.r: F = None
        self.u: E = None
        self.t: E = None
        self.txt = txt

e = A("e")
a = B("a")
g = C("g")
i = D("i")
l = E("l")
f = F("f")
m = C("m")
c = F("c")
j = C("j")

e.r = c
e.w = i
e.t = l
e.s = l
e.x = m
a.w = l
a.v = f
a.s = g
g.q = a
g.v = f
g.x = f
g.y = j
g.r = j
g.t = l
i.w = l
i.t = a
l.t = e
l.r = e
f.s = c
f.r = c
f.u = l
f.t = l
m.q = a
m.v = f
m.y = j
m.t = l
m.r = g
m.x = c
c.s = f
c.r = f
c.u = l
c.t = l
j.q = a
j.v = c
j.y = m
j.r = m
j.t = l
j.x = f
assert f.s.r.u.r.r.u.txt == "l"