class A:
    def __init__(self, txt: str):
        self.u: C = None
        self.x: G = None
        self.txt = txt

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.y: C = None
        self.q: B = None
        self.w: D = None
        self.txt = txt

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

e = A("e")
c = B("c")
g = C("g")
d = D("d")
i = E("i")
a = F("a")
k = G("k")
b = D("b")
j = E("j")
m = F("m")

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.y: C = None
        self.q: B = None
        self.w: D = None
        self.txt = txt

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

e = A("e")
c = B("c")
g = C("g")
d = D("d")
i = E("i")
a = F("a")
k = G("k")
b = D("b")
j = E("j")
m = F("m")

e.u = g
e.x = k
c.s = k
c.q = e
g.y = i
g.s = i
g.t = c
g.r = c
g.o = a
g.x = k
d.u = k
d.v = c
d.s = e
d.x = g
d.t = m
i.y = c
i.w = e
i.u = k
i.o = d
i.z = b
a.y = g
a.q = c
a.w = b
k.v = g
k.s = i
b.u = k
b.v = c
b.s = e
b.x = g
b.t = a
j.y = c
j.w = e
j.u = k
j.o = d
j.z = b
m.y = g
m.q = c
m.w = d
assert j.u.s.o.u.s.txt == "i"