class A:
    def __init__(self, txt: str):
        self.s: D = None
        self.x: D = None
        self.v: B = None
        self.z: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.o: F = None
        self.y: G = None
        self.q: G = None
        self.v: E = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.p: G = None
        self.v: A = None
        self.x: F = None
        self.o: B = None
        self.u: G = None
        self.txt = txt

c = A("c")
h = B("h")
l = C("l")
e = D("e")
b = E("b")
m = F("m")
f = G("f")
a = G("a")
k = F("k")
i = E("i")

c.s = e
c.x = e
c.v = h
c.z = h
h.x = e
h.v = f
h.p = c
h.r = c
l.o = k
l.y = a
l.q = a
l.v = b
e.z = b
b.y = c
m.u = f
m.s = f
m.p = k
m.t = h
m.x = h
m.o = c
m.v = i
f.p = a
f.u = a
f.v = c
f.x = m
f.o = h
a.p = f
a.u = f
a.v = c
a.x = k
a.o = h
k.u = f
k.p = m
k.t = h
k.x = h
k.o = c
k.v = b
k.s = a
i.y = c
assert e.z.y.s.z.y.v.v.v.s.z.txt == "
class A:
    def __init__(self, txt: str):
        self.s: D = None
        self.x: D = None
        self.v: B = None
        self.z: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.o: F = None
        self.y: G = None
        self.q: G = None
        self.v: E = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.p: G = None
        self.v: A = None
        self.x: F = None
        self.o: B = None
        self.u: G = None
        self.txt = txt

c = A("c")
h = B("h")
l = C("l")
e = D("e")
b = E("b")
m = F("m")
f = G("f")
a = G("a")
k = F("k")
i = E("i")

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