class A:
    def __init__(self, txt: str):
        self.s: E = None
        self.t: E = None
        self.r: G = None
        self.u: G = None
        self.y: E = None
        self.o: I = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.p: G = None
        self.s: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.q: I = None
        self.t: H = None
        self.u: H = None
        self.y: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: D = None
        self.y: E = None
        self.s: D = None
        self.o: G = None
        self.r: A = None
        self.t: I = None
        self.q: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: F = None
        self.v: D = None
        self.w: E = None
        self.z: E = None
        self.r: I = None
        self.y: I = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.x: A = None
        self.q: B = None
        self.t: H = None
        self.z: B = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.p: G = None
        self.s: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.q: I = None
        self.t: H = None
        self.u: H = None
        self.y: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: D = None
        self.y: E = None
        self.s: D = None
        self.o: G = None
        self.r: A = None
        self.t: I = None
        self.q: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: F = None
        self.v: D = None
        self.w: E = None
        self.z: E = None
        self.r: I = None
        self.y: I = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.x: A = None
        self.q: B = None
        self.t: H = None
        self.z: B = None
        self.txt = txt

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

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