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

class B:
    def __init__(self, txt: str):
        self.u: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: F = None
        self.q: G = None
        self.o: F = None
        self.r: A = None
        self.y: B = None
        self.w: A = None
        self.u: F = None
        self.s: H = None
        self.x: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: F = None
        self.q: H = None
        self.p: D = None
        self.z: H = None
        self.r: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: I = None
        self.w: H = None
        self.o: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: E = None
        self.v: C = None
        self.z: H = None
        self.q: A = None
        self.t: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: F = None
        self.o: H = None
        self.v: A = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.q: F = None
        self.s: C = None
        self.t: A = None
        self.z: E = None
        self.u: E = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.u: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: F = None
        self.q: G = None
        self.o: F = None
        self.r: A = None
        self.y: B = None
        self.w: A = None
        self.u: F = None
        self.s: H = None
        self.x: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: F = None
        self.q: H = None
        self.p: D = None
        self.z: H = None
        self.r: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: I = None
        self.w: H = None
        self.o: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: E = None
        self.v: C = None
        self.z: H = None
        self.q: A = None
        self.t: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: F = None
        self.o: H = None
        self.v: A = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.q: F = None
        self.s: C = None
        self.t: A = None
        self.z: E = None
        self.u: E = None
        self.txt = txt

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

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