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

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

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

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

class E:
    def __init__(self, txt: str):
        self.w: B = None
        self.s: E = None
        self.x: C = None
        self.p: B = None
        self.y: C = None
        self.z: B = None
        self.v: A = None
        self.u: E = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: B = None
        self.q: C = None
        self.y: H = None
        self.p: G = None
        self.v: I = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.w: E = None
        self.u: A = None
        self.q: D = None
        self.o: I = None
        self.p: B = None
        self.y: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: F = None
        self.p: E = None
        self.o: E = None
        self.txt = txt

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.w: B = None
        self.s: E = None
        self.x: C = None
        self.p: B = None
        self.y: C = None
        self.z: B = None
        self.v: A = None
        self.u: E = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: B = None
        self.q: C = None
        self.y: H = None
        self.p: G = None
        self.v: I = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.w: E = None
        self.u: A = None
        self.q: D = None
        self.o: I = None
        self.p: B = None
        self.y: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: F = None
        self.p: E = None
        self.o: E = None
        self.txt = txt

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

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