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

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

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

class D:
    def __init__(self, txt: str):
        self.p: G = None
        self.w: B = None
        self.q: B = None
        self.x: A = None
        self.s: G = None
        self.y: B = None
        self.z: G = None
        self.u: H = None
        self.t: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: I = None
        self.z: H = None
        self.v: D = None
        self.s: I = None
        self.u: A = None
        self.q: C = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.w: G = None
        self.z: G = None
        self.y: G = None
        self.x: A = None
        self.v: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.u: E = None
        self.q: E = None
        self.x: D = None
        self.v: E = None
        self.w: D = None
        self.o: A = None
        self.t: C = None
        self.r: C = None
        self.p: A = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.p: G = None
        self.w: B = None
        self.q: B = None
        self.x: A = None
        self.s: G = None
        self.y: B = None
        self.z: G = None
        self.u: H = None
        self.t: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: I = None
        self.z: H = None
        self.v: D = None
        self.s: I = None
        self.u: A = None
        self.q: C = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.w: G = None
        self.z: G = None
        self.y: G = None
        self.x: A = None
        self.v: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.u: E = None
        self.q: E = None
        self.x: D = None
        self.v: E = None
        self.w: D = None
        self.o: A = None
        self.t: C = None
        self.r: C = None
        self.p: A = None
        self.txt = txt

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

m.o = k
m.y = i
e.o = m
a.x = c
a.v = c
a.o = i
j.p = i
j.s = i
j.z = i
j.w = e
j.q = e
j.y = e
j.x = m
j.u = f
j.t = f
c.r = d
c.s = d
c.z = f
c.v = j
c.u = m
c.q = a
k.u = f
i.s = c
i.o = d
i.x = m
f.w = i
f.z = i
f.y = i
f.v = i
f.x = m
d.u = c
d.q = c
d.v = c
d.x = j
d.w = j
d.o = m
d.p = m
d.t = a
d.r = a
assert m.o.u.x.y.o.t.o.txt == "i"