class A:
    def __init__(self, txt: str):
        self.v: C = None
        self.s: D = None
        self.x: I = None
        self.q: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: A = None
        self.o: H = None
        self.p: D = None
        self.t: H = None
        self.v: E = None
        self.q: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: G = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.v: D = None
        self.x: H = None
        self.s: B = None
        self.w: F = None
        self.y: A = None
        self.u: G = None
        self.q: F = None
        self.p: G = None
        self.o: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: E = None
        self.v: G = None
        self.p: E = None
        self.t: H = None
        self.x: D = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.y: D = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.s: A = None
        self.o: H = None
        self.p: D = None
        self.t: H = None
        self.v: E = None
        self.q: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: G = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.v: D = None
        self.x: H = None
        self.s: B = None
        self.w: F = None
        self.y: A = None
        self.u: G = None
        self.q: F = None
        self.p: G = None
        self.o: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: E = None
        self.v: G = None
        self.p: E = None
        self.t: H = None
        self.x: D = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.y: D = None
        self.txt = txt

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

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

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