class A:
    def __init__(self, txt: str):
        self.s: F = None
        self.r: G = None
        self.v: G = None
        self.x: G = None
        self.p: F = None
        self.y: F = None
        self.z: F = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.r: A = None
        self.o: F = None
        self.y: D = None
        self.v: G = None
        self.t: C = None
        self.x: F = None
        self.p: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: A = None
        self.y: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: D = None
        self.t: C = None
        self.z: F = None
        self.y: G = None
        self.u: F = None
        self.s: F = None
        self.q: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: C = None
        self.u: A = None
        self.r: A = None
        self.txt = txt

e = A("e")
n = B("n")
b = C("b")
d = D("d")
m = E("m")
k = F("k")
j = G("j")
l = G("l")
c = C("c")

e.s = k
e.p = k
e.y = k
e.z = k
e.r = j
e.v = l
e.x = l
n.t = d
n.o = m
b.r = e
b.p = e
b.o = k
b.x = k
b.y = d
b.v = j
b.t = c
d.x = e
d.y = l
m.x = d
m.t = c
m.z = k
m.u = k
m.s = k
m.y = l
m.q = n
k.y = m
j.p = c
j.u = e
j.r = e
l.p = c
l.u = e
l.r = e
c.r = e
c.p = e
c.o = k
c.x = k
c.y = d
c.v = j
c.t = b
assert l.p.t.t.p.v.p.t.txt == "
class A:
    def __init__(self, txt: str):
        self.s: F = None
        self.r: G = None
        self.v: G = None
        self.x: G = None
        self.p: F = None
        self.y: F = None
        self.z: F = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.r: A = None
        self.o: F = None
        self.y: D = None
        self.v: G = None
        self.t: C = None
        self.x: F = None
        self.p: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: A = None
        self.y: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: D = None
        self.t: C = None
        self.z: F = None
        self.y: G = None
        self.u: F = None
        self.s: F = None
        self.q: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: C = None
        self.u: A = None
        self.r: A = None
        self.txt = txt

e = A("e")
n = B("n")
b = C("b")
d = D("d")
m = E("m")
k = F("k")
j = G("j")
l = G("l")
c = C("c")

e.s = k
e.p = k
e.y = k
e.z = k
e.r = j
e.v = l
e.x = l
n.t = d
n.o = m
b.r = e
b.p = e
b.o = k
b.x = k
b.y = d
b.v = j
b.t = c
d.x = e
d.y = l
m.x = d
m.t = c
m.z = k
m.u = k
m.s = k
m.y = l
m.q = n
k.y = m
j.p = c
j.u = e
j.r = e
l.p = c
l.u = e
l.r = e
c.r = e
c.p = e
c.o = k
c.x = k
c.y = d
c.v = j
c.t = b
assert l.p.t.t.p.v.p.t.txt == "b"