class A:
    def __init__(self, txt: str):
        self.q: C = None
        self.r: J = None
        self.z: J = None
        self.w: F = None
        self.v: I = None
        self.u: E = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.y: B = None
        self.x: J = None
        self.p: D = None
        self.o: J = None
        self.v: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: H = None
        self.txt = txt

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

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

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

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

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.y: B = None
        self.x: J = None
        self.p: D = None
        self.o: J = None
        self.v: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: H = None
        self.txt = txt

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

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

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

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

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

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