class A:
    def __init__(self, txt: str):
        self.z: F = None
        self.x: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: C = None
        self.q: E = None
        self.s: C = None
        self.v: D = None
        self.p: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.r: B = None
        self.u: E = None
        self.y: B = None
        self.w: B = None
        self.q: B = None
        self.p: E = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.y: C = None
        self.t: D = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.z: C = None
        self.q: E = None
        self.s: C = None
        self.v: D = None
        self.p: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.r: B = None
        self.u: E = None
        self.y: B = None
        self.w: B = None
        self.q: B = None
        self.p: E = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.y: C = None
        self.t: D = None
        self.txt = txt

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

j.z = d
j.x = e
f.z = e
f.s = e
f.q = i
f.v = l
f.p = g
e.v = l
e.x = l
e.o = f
e.r = d
e.q = m
l.r = f
l.y = f
l.w = f
l.q = f
l.u = i
l.p = i
i.x = l
i.t = l
i.y = e
i.s = d
m.y = e
m.t = l
d.y = e
d.t = l
g.y = e
g.t = l
assert i.y.q.t.p.txt == "i"