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

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

class C:
    def __init__(self, txt: str):
        self.r: F = None
        self.z: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: G = None
        self.u: D = None
        self.p: F = None
        self.v: B = None
        self.t: B = None
        self.w: A = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.y: A = None
        self.txt = txt

m = A("m")
k = B("k")
f = C("f")
n = D("n")
d = E("d")
i = F("i")
c = G("c")
e = H("e")
l = A("l")

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

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

class C:
    def __init__(self, txt: str):
        self.r: F = None
        self.z: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: G = None
        self.u: D = None
        self.p: F = None
        self.v: B = None
        self.t: B = None
        self.w: A = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.y: A = None
        self.txt = txt

m = A("m")
k = B("k")
f = C("f")
n = D("n")
d = E("d")
i = F("i")
c = G("c")
e = H("e")
l = A("l")

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