class A:
    def __init__(self, txt: str):
        self.v: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.o: G = None
        self.u: E = None
        self.x: A = None
        self.v: G = None
        self.y: D = None
        self.r: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.w: G = None
        self.z: F = None
        self.p: B = None
        self.y: G = None
        self.r: E = None
        self.s: B = None
        self.q: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.r: C = None
        self.u: C = None
        self.o: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: C = None
        self.o: C = None
        self.p: F = None
        self.txt = txt

m = A("m")
d = B("d")
j = C("j")
a = D("a")
h = E("h")
b = F("b")
n = G("n")
i = G("i")
k = D("k")

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

class B:
    def __init__(self, txt: str):
        self.o: G = None
        self.u: E = None
        self.x: A = None
        self.v: G = None
        self.y: D = None
        self.r: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.w: G = None
        self.z: F = None
        self.p: B = None
        self.y: G = None
        self.r: E = None
        self.s: B = None
        self.q: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.r: C = None
        self.u: C = None
        self.o: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: C = None
        self.o: C = None
        self.p: F = None
        self.txt = txt

m = A("m")
d = B("d")
j = C("j")
a = D("a")
h = E("h")
b = F("b")
n = G("n")
i = G("i")
k = D("k")

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