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

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

class C:
    def __init__(self, txt: str):
        self.w: A = None
        self.v: D = None
        self.o: B = None
        self.x: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: B = None
        self.o: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.u: F = None
        self.v: F = None
        self.y: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: B = None
        self.r: A = None
        self.w: F = None
        self.u: E = None
        self.v: H = None
        self.s: F = None
        self.y: D = None
        self.q: H = None
        self.txt = txt

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

i = A("i")
m = B("m")
c = C("c")
h = D("h")
b = E("b")
g = F("g")
d = G("d")
k = H("k")
a = G("a")
l = F("l")

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

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

class C:
    def __init__(self, txt: str):
        self.w: A = None
        self.v: D = None
        self.o: B = None
        self.x: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: B = None
        self.o: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.u: F = None
        self.v: F = None
        self.y: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: B = None
        self.r: A = None
        self.w: F = None
        self.u: E = None
        self.v: H = None
        self.s: F = None
        self.y: D = None
        self.q: H = None
        self.txt = txt

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

i = A("i")
m = B("m")
c = C("c")
h = D("h")
b = E("b")
g = F("g")
d = G("d")
k = H("k")
a = G("a")
l = F("l")

i.o = b
m.u = k
m.r = b
m.t = l
m.q = i
c.w = i
c.v = h
c.x = h
c.o = m
h.w = m
h.o = m
b.o = l
b.y = i
g.u = l
g.v = l
g.y = h
d.z = m
d.r = i
d.w = l
d.s = l
d.u = b
d.v = k
d.q = k
d.y = h
k.t = m
k.o = b
k.s = l
a.z = m
a.r = i
a.w = g
a.s = g
a.u = b
a.v = k
a.q = k
a.y = h
l.u = g
l.v = g
l.y = h
assert b.y.o.y.o.y.o.y.o.txt == "b"