class A:
    def __init__(self, txt: str):
        self.t: F = None
        self.q: E = None
        self.o: E = None
        self.v: G = None
        self.w: E = None
        self.z: C = None
        self.s: E = None
        self.y: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.w: E = None
        self.y: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: E = None
        self.y: A = None
        self.w: I = None
        self.z: F = None
        self.t: D = None
        self.v: D = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.v: I = None
        self.y: I = None
        self.r: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: I = None
        self.p: E = None
        self.x: B = None
        self.t: I = None
        self.r: D = None
        self.y: I = None
        self.o: C = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.y: E = None
        self.w: H = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.w: E = None
        self.y: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: E = None
        self.y: A = None
        self.w: I = None
        self.z: F = None
        self.t: D = None
        self.v: D = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.v: I = None
        self.y: I = None
        self.r: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: I = None
        self.p: E = None
        self.x: B = None
        self.t: I = None
        self.r: D = None
        self.y: I = None
        self.o: C = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.y: E = None
        self.w: H = None
        self.txt = txt

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

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