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

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

class C:
    def __init__(self, txt: str):
        self.s: G = None
        self.t: B = None
        self.u: B = None
        self.z: A = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.w: F = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: H = None
        self.w: C = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.t: H = None
        self.y: G = None
        self.x: F = None
        self.w: B = None
        self.o: B = None
        self.z: D = None
        self.u: E = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.s: G = None
        self.t: B = None
        self.u: B = None
        self.z: A = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.w: F = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: H = None
        self.w: C = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.t: H = None
        self.y: G = None
        self.x: F = None
        self.w: B = None
        self.o: B = None
        self.z: D = None
        self.u: E = None
        self.txt = txt

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

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