class A:
    def __init__(self, txt: str):
        self.o: B = None
        self.t: I = None
        self.p: E = None
        self.r: D = None
        self.u: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: C = None
        self.s: D = None
        self.t: F = None
        self.q: C = None
        self.z: D = None
        self.o: D = None
        self.txt = txt

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.u: D = None
        self.s: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.q: I = None
        self.v: D = None
        self.s: A = None
        self.w: G = None
        self.u: D = None
        self.t: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: C = None
        self.s: D = None
        self.z: G = None
        self.p: A = None
        self.q: G = None
        self.txt = txt

j = A("j")
k = B("k")
c = C("c")
l = D("l")
d = E("d")
g = F("g")
i = G("i")
b = H("b")
e = I("e")

j.o = k
j.t = e
j.p = d
j.r = l
j.u = g
k.u = c
k.q = c
k.s = l
k.z = l
k.o = l
k.t = g
c.y = b
c.w = e
c.x = d
c.r = j
l.p = b
l.r = b
l.w = d
l.z = k
l.t = i
l.o = c
l.x = j
d.q = k
d.t = k
d.x = c
d.v = i
g.y = k
g.z = e
g.v = l
i.u = l
i.s = c
b.q = e
b.v = l
b.u = l
b.s = j
b.w = i
b.t = g
e.w = c
e.s = l
e.z = i
e.q = i
e.p = j
assert b.s.r.z.t.y.q.txt == "
class A:
    def __init__(self, txt: str):
        self.o: B = None
        self.t: I = None
        self.p: E = None
        self.r: D = None
        self.u: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: C = None
        self.s: D = None
        self.t: F = None
        self.q: C = None
        self.z: D = None
        self.o: D = None
        self.txt = txt

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.u: D = None
        self.s: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.q: I = None
        self.v: D = None
        self.s: A = None
        self.w: G = None
        self.u: D = None
        self.t: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: C = None
        self.s: D = None
        self.z: G = None
        self.p: A = None
        self.q: G = None
        self.txt = txt

j = A("j")
k = B("k")
c = C("c")
l = D("l")
d = E("d")
g = F("g")
i = G("i")
b = H("b")
e = I("e")

j.o = k
j.t = e
j.p = d
j.r = l
j.u = g
k.u = c
k.q = c
k.s = l
k.z = l
k.o = l
k.t = g
c.y = b
c.w = e
c.x = d
c.r = j
l.p = b
l.r = b
l.w = d
l.z = k
l.t = i
l.o = c
l.x = j
d.q = k
d.t = k
d.x = c
d.v = i
g.y = k
g.z = e
g.v = l
i.u = l
i.s = c
b.q = e
b.v = l
b.u = l
b.s = j
b.w = i
b.t = g
e.w = c
e.s = l
e.z = i
e.q = i
e.p = j
assert b.s.r.z.t.y.q.txt == "c"