class A:
    def __init__(self, txt: str):
        self.y: D = None
        self.t: E = None
        self.w: B = None
        self.u: E = None
        self.o: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: H = None
        self.v: E = None
        self.y: G = None
        self.u: H = None
        self.s: A = None
        self.w: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: H = None
        self.z: H = None
        self.w: F = None
        self.t: C = None
        self.r: H = None
        self.u: F = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.z: C = None
        self.t: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: A = None
        self.s: G = None
        self.v: I = None
        self.p: C = None
        self.x: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: D = None
        self.z: D = None
        self.p: E = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.t: H = None
        self.v: E = None
        self.y: G = None
        self.u: H = None
        self.s: A = None
        self.w: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: H = None
        self.z: H = None
        self.w: F = None
        self.t: C = None
        self.r: H = None
        self.u: F = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.z: C = None
        self.t: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: A = None
        self.s: G = None
        self.v: I = None
        self.p: C = None
        self.x: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: D = None
        self.z: D = None
        self.p: E = None
        self.txt = txt

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

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