class A:
    def __init__(self, txt: str):
        self.y: C = None
        self.p: I = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.v: G = None
        self.z: I = None
        self.y: G = None
        self.r: F = None
        self.t: F = None
        self.o: D = None
        self.p: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: I = None
        self.w: B = None
        self.p: J = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: B = None
        self.t: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: B = None
        self.w: H = None
        self.s: G = None
        self.y: C = None
        self.p: A = None
        self.x: D = None
        self.r: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: E = None
        self.q: I = None
        self.w: A = None
        self.u: E = None
        self.r: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: D = None
        self.v: D = None
        self.u: E = None
        self.txt = txt

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.v: G = None
        self.z: I = None
        self.y: G = None
        self.r: F = None
        self.t: F = None
        self.o: D = None
        self.p: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: I = None
        self.w: B = None
        self.p: J = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: B = None
        self.t: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: B = None
        self.w: H = None
        self.s: G = None
        self.y: C = None
        self.p: A = None
        self.x: D = None
        self.r: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: E = None
        self.q: I = None
        self.w: A = None
        self.u: E = None
        self.r: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: D = None
        self.v: D = None
        self.u: E = None
        self.txt = txt

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

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

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

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