class A:
    def __init__(self, txt: str):
        self.y: B = None
        self.x: D = None
        self.o: G = None
        self.u: G = None
        self.s: G = None
        self.p: B = None
        self.t: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.x: G = None
        self.r: I = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.q: F = None
        self.r: F = None
        self.v: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: B = None
        self.q: A = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.v: E = None
        self.p: D = None
        self.q: B = None
        self.w: G = None
        self.x: E = None
        self.y: D = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.x: G = None
        self.r: I = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.q: F = None
        self.r: F = None
        self.v: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: B = None
        self.q: A = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.v: E = None
        self.p: D = None
        self.q: B = None
        self.w: G = None
        self.x: E = None
        self.y: D = None
        self.txt = txt

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

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

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