class A:
    def __init__(self, txt: str):
        self.v: F = None
        self.r: F = None
        self.p: E = None
        self.w: F = None
        self.t: I = None
        self.o: C = None
        self.u: F = None
        self.x: B = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.q: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: F = None
        self.s: G = None
        self.u: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.q: D = None
        self.txt = txt

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

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.q: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: F = None
        self.s: G = None
        self.u: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.q: D = None
        self.txt = txt

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

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

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

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