class A:
    def __init__(self, txt: str):
        self.t: D = None
        self.w: F = None
        self.u: A = None
        self.r: C = None
        self.x: D = None
        self.s: G = None
        self.p: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.v: D = None
        self.w: B = None
        self.q: A = None
        self.u: E = None
        self.t: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: E = None
        self.z: A = None
        self.x: A = None
        self.y: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: A = None
        self.r: A = None
        self.s: C = None
        self.v: F = None
        self.p: F = None
        self.y: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.r: A = None
        self.q: B = None
        self.z: C = None
        self.w: B = None
        self.s: C = None
        self.t: G = None
        self.y: G = None
        self.txt = txt

f = A("f")
n = B("n")
d = C("d")
i = D("i")
k = E("k")
m = F("m")
a = G("a")
b = G("b")
e = A("e")

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

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

class C:
    def __init__(self, txt: str):
        self.v: D = None
        self.w: B = None
        self.q: A = None
        self.u: E = None
        self.t: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: E = None
        self.z: A = None
        self.x: A = None
        self.y: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: A = None
        self.r: A = None
        self.s: C = None
        self.v: F = None
        self.p: F = None
        self.y: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.r: A = None
        self.q: B = None
        self.z: C = None
        self.w: B = None
        self.s: C = None
        self.t: G = None
        self.y: G = None
        self.txt = txt

f = A("f")
n = B("n")
d = C("d")
i = D("i")
k = E("k")
m = F("m")
a = G("a")
b = G("b")
e = A("e")

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