class A:
    def __init__(self, txt: str):
        self.s: F = None
        self.r: F = None
        self.q: H = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.x: C = None
        self.r: H = None
        self.v: A = None
        self.u: E = None
        self.t: E = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.r: H = None
        self.p: C = None
        self.t: H = None
        self.x: G = None
        self.o: H = None
        self.w: D = None
        self.s: C = None
        self.u: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: H = None
        self.y: D = None
        self.r: D = None
        self.o: A = None
        self.w: A = None
        self.v: F = None
        self.p: H = None
        self.txt = txt

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.x: C = None
        self.r: H = None
        self.v: A = None
        self.u: E = None
        self.t: E = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.r: H = None
        self.p: C = None
        self.t: H = None
        self.x: G = None
        self.o: H = None
        self.w: D = None
        self.s: C = None
        self.u: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: H = None
        self.y: D = None
        self.r: D = None
        self.o: A = None
        self.w: A = None
        self.v: F = None
        self.p: H = None
        self.txt = txt

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

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

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