class A:
    def __init__(self, txt: str):
        self.q: E = None
        self.t: G = None
        self.r: I = None
        self.y: C = None
        self.x: D = None
        self.p: H = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.z: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.p: A = None
        self.y: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: A = None
        self.u: F = None
        self.x: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: G = None
        self.x: E = None
        self.r: B = None
        self.q: A = None
        self.o: G = None
        self.z: J = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: J = None
        self.s: F = None
        self.r: F = None
        self.v: C = None
        self.t: A = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.o: D = None
        self.y: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.s: D = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.z: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.p: A = None
        self.y: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: A = None
        self.u: F = None
        self.x: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: G = None
        self.x: E = None
        self.r: B = None
        self.q: A = None
        self.o: G = None
        self.z: J = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: J = None
        self.s: F = None
        self.r: F = None
        self.v: C = None
        self.t: A = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.o: D = None
        self.y: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.s: D = None
        self.txt = txt

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

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