class A:
    def __init__(self, txt: str):
        self.u: G = None
        self.p: F = None
        self.z: E = None
        self.v: E = None
        self.t: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.o: A = None
        self.s: E = None
        self.z: E = None
        self.v: A = None
        self.u: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: G = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.t: D = None
        self.z: G = None
        self.u: C = None
        self.w: B = None
        self.q: G = None
        self.y: C = None
        self.o: E = None
        self.txt = txt

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

c = A("c")
i = B("i")
d = C("d")
h = D("h")
m = E("m")
f = F("f")
b = G("b")
k = G("k")
j = E("j")
l = F("l")

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

class B:
    def __init__(self, txt: str):
        self.o: A = None
        self.s: E = None
        self.z: E = None
        self.v: A = None
        self.u: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: G = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.t: D = None
        self.z: G = None
        self.u: C = None
        self.w: B = None
        self.q: G = None
        self.y: C = None
        self.o: E = None
        self.txt = txt

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

c = A("c")
i = B("i")
d = C("d")
h = D("h")
m = E("m")
f = F("f")
b = G("b")
k = G("k")
j = E("j")
l = F("l")

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