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

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

class C:
    def __init__(self, txt: str):
        self.w: E = None
        self.s: E = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.o: G = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.w: E = None
        self.s: E = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.o: G = None
        self.txt = txt

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

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

n.o = j
n.z = j
n.v = f
n.p = f
n.x = e
n.u = e
n.y = i
j.p = n
j.y = i
j.t = i
c.w = d
c.s = d
f.v = d
f.p = m
f.z = c
d.s = i
d.z = b
e.o = b
m.p = d
m.v = e
m.y = c
m.s = c
m.w = f
i.o = j
i.z = j
i.v = f
i.p = f
i.x = e
i.u = e
i.y = n
b.p = d
b.v = e
b.y = c
b.s = c
b.w = f
assert b.v.o.v.o.p.s.v.v.s.txt == "i"