class A:
    def __init__(self, txt: str):
        self.v: G = None
        self.y: F = None
        self.u: H = None
        self.w: I = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.r: H = None
        self.v: G = None
        self.z: G = None
        self.o: I = None
        self.s: E = None
        self.t: A = None
        self.w: D = None
        self.p: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: H = None
        self.u: D = None
        self.t: B = None
        self.v: F = None
        self.r: E = None
        self.z: I = None
        self.s: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.w: I = None
        self.q: I = None
        self.u: D = None
        self.r: F = None
        self.y: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: D = None
        self.v: E = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.q: I = None
        self.s: B = None
        self.w: B = None
        self.z: E = None
        self.v: I = None
        self.p: H = None
        self.o: E = None
        self.u: D = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.r: H = None
        self.v: G = None
        self.z: G = None
        self.o: I = None
        self.s: E = None
        self.t: A = None
        self.w: D = None
        self.p: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: H = None
        self.u: D = None
        self.t: B = None
        self.v: F = None
        self.r: E = None
        self.z: I = None
        self.s: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.w: I = None
        self.q: I = None
        self.u: D = None
        self.r: F = None
        self.y: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: D = None
        self.v: E = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.q: I = None
        self.s: B = None
        self.w: B = None
        self.z: E = None
        self.v: I = None
        self.p: H = None
        self.o: E = None
        self.u: D = None
        self.txt = txt

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

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

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