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

class B:
    def __init__(self, txt: str):
        self.x: F = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.w: B = None
        self.p: G = None
        self.txt = txt

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

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.x: F = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.w: B = None
        self.p: G = None
        self.txt = txt

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

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

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

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

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