class A:
    def __init__(self, txt: str):
        self.t: B = None
        self.r: B = None
        self.y: E = None
        self.z: D = None
        self.w: E = None
        self.v: B = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.y: G = None
        self.w: A = None
        self.u: A = None
        self.r: C = None
        self.t: G = None
        self.p: B = None
        self.o: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: D = None
        self.w: C = None
        self.x: B = None
        self.s: G = None
        self.v: E = None
        self.txt = txt

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

f = A("f")
n = B("n")
m = C("m")
i = D("i")
c = E("c")
j = F("j")
h = G("h")

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.y: G = None
        self.w: A = None
        self.u: A = None
        self.r: C = None
        self.t: G = None
        self.p: B = None
        self.o: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: D = None
        self.w: C = None
        self.x: B = None
        self.s: G = None
        self.v: E = None
        self.txt = txt

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

f = A("f")
n = B("n")
m = C("m")
i = D("i")
c = E("c")
j = F("j")
h = G("h")

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