class A:
    def __init__(self, txt: str):
        self.z: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: A = None
        self.p: B = None
        self.w: F = None
        self.r: G = None
        self.u: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: B = None
        self.w: E = None
        self.o: G = None
        self.u: G = None
        self.p: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: G = None
        self.x: B = None
        self.o: G = None
        self.w: G = None
        self.r: G = None
        self.u: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: E = None
        self.w: E = None
        self.q: B = None
        self.r: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: A = None
        self.p: B = None
        self.t: G = None
        self.z: G = None
        self.x: G = None
        self.s: E = None
        self.o: F = None
        self.txt = txt

i = A("i")
m = B("m")
k = C("k")
e = D("e")
a = E("a")
j = F("j")
f = G("f")
b = G("b")
c = B("c")

i.z = e
m.z = i
m.p = c
m.w = j
m.r = f
m.u = a
k.x = c
k.w = a
k.o = b
k.u = f
k.p = j
e.w = i
a.t = f
a.o = f
a.x = m
a.u = m
a.w = b
a.r = b
j.v = a
j.w = a
j.q = m
j.r = i
f.r = i
f.p = c
f.t = b
f.z = b
f.x = b
f.s = a
f.o = j
b.r = i
b.p = c
b.t = f
b.z = f
b.x = f
b.s = a
b.o = j
c.z = i
c.p = m
c.w = j
c.r = b
c.u = a
assert j.q.u.w.s.t.r.txt == "
class A:
    def __init__(self, txt: str):
        self.z: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: A = None
        self.p: B = None
        self.w: F = None
        self.r: G = None
        self.u: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: B = None
        self.w: E = None
        self.o: G = None
        self.u: G = None
        self.p: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: G = None
        self.x: B = None
        self.o: G = None
        self.w: G = None
        self.r: G = None
        self.u: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: E = None
        self.w: E = None
        self.q: B = None
        self.r: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: A = None
        self.p: B = None
        self.t: G = None
        self.z: G = None
        self.x: G = None
        self.s: E = None
        self.o: F = None
        self.txt = txt

i = A("i")
m = B("m")
k = C("k")
e = D("e")
a = E("a")
j = F("j")
f = G("f")
b = G("b")
c = B("c")

i.z = e
m.z = i
m.p = c
m.w = j
m.r = f
m.u = a
k.x = c
k.w = a
k.o = b
k.u = f
k.p = j
e.w = i
a.t = f
a.o = f
a.x = m
a.u = m
a.w = b
a.r = b
j.v = a
j.w = a
j.q = m
j.r = i
f.r = i
f.p = c
f.t = b
f.z = b
f.x = b
f.s = a
f.o = j
b.r = i
b.p = c
b.t = f
b.z = f
b.x = f
b.s = a
b.o = j
c.z = i
c.p = m
c.w = j
c.r = b
c.u = a
assert j.q.u.w.s.t.r.txt == "i"