class A:
    def __init__(self, txt: str):
        self.q: F = None
        self.s: E = None
        self.v: D = None
        self.x: E = None
        self.o: C = None
        self.p: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.s: F = None
        self.z: E = None
        self.q: A = None
        self.r: D = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.x: E = None
        self.s: B = None
        self.t: E = None
        self.u: D = None
        self.w: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: A = None
        self.w: F = None
        self.x: D = None
        self.u: E = None
        self.p: A = None
        self.o: B = None
        self.q: D = None
        self.txt = txt

c = A("c")
a = B("a")
n = C("n")
b = D("b")
i = E("i")
f = F("f")
l = G("l")
k = B("k")
j = G("j")

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

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

class C:
    def __init__(self, txt: str):
        self.s: F = None
        self.z: E = None
        self.q: A = None
        self.r: D = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.x: E = None
        self.s: B = None
        self.t: E = None
        self.u: D = None
        self.w: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: A = None
        self.w: F = None
        self.x: D = None
        self.u: E = None
        self.p: A = None
        self.o: B = None
        self.q: D = None
        self.txt = txt

c = A("c")
a = B("a")
n = C("n")
b = D("b")
i = E("i")
f = F("f")
l = G("l")
k = B("k")
j = G("j")

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