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

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

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

class D:
    def __init__(self, txt: str):
        self.r: E = None
        self.s: G = None
        self.o: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: B = None
        self.o: F = None
        self.u: F = None
        self.v: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: D = None
        self.o: G = None
        self.u: D = None
        self.p: E = None
        self.x: D = None
        self.txt = txt

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

d = A("d")
e = B("e")
j = C("j")
b = D("b")
f = E("f")
g = F("g")
k = G("k")
a = F("a")

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

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

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

class D:
    def __init__(self, txt: str):
        self.r: E = None
        self.s: G = None
        self.o: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: B = None
        self.o: F = None
        self.u: F = None
        self.v: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: D = None
        self.o: G = None
        self.u: D = None
        self.p: E = None
        self.x: D = None
        self.txt = txt

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

d = A("d")
e = B("e")
j = C("j")
b = D("b")
f = E("f")
g = F("g")
k = G("k")
a = F("a")

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