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

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

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

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

class E:
    def __init__(self, txt: str):
        self.q: G = None
        self.t: G = None
        self.u: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: A = None
        self.z: I = None
        self.s: B = None
        self.q: B = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.u: D = None
        self.o: D = None
        self.w: G = None
        self.x: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.v: E = None
        self.p: G = None
        self.x: D = None
        self.txt = txt

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.q: G = None
        self.t: G = None
        self.u: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: A = None
        self.z: I = None
        self.s: B = None
        self.q: B = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.u: D = None
        self.o: D = None
        self.w: G = None
        self.x: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.v: E = None
        self.p: G = None
        self.x: D = None
        self.txt = txt

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

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