class A:
    def __init__(self, txt: str):
        self.p: D = None
        self.z: E = None
        self.x: E = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.r: D = None
        self.z: G = None
        self.v: A = None
        self.u: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: D = None
        self.u: G = None
        self.v: A = None
        self.z: C = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: D = None
        self.p: A = None
        self.w: A = None
        self.y: C = None
        self.o: A = None
        self.s: E = None
        self.z: B = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.r: D = None
        self.z: G = None
        self.v: A = None
        self.u: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: D = None
        self.u: G = None
        self.v: A = None
        self.z: C = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: D = None
        self.p: A = None
        self.w: A = None
        self.y: C = None
        self.o: A = None
        self.s: E = None
        self.z: B = None
        self.txt = txt

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

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

e.p = c
e.z = a
e.x = a
k.y = a
k.w = g
m.r = c
m.z = l
m.v = i
m.u = n
b.o = c
b.u = n
b.v = i
b.z = m
a.t = n
a.v = n
a.u = n
a.o = i
a.p = g
g.t = b
g.p = i
g.w = e
g.o = e
g.y = m
g.s = a
g.z = k
n.x = m
n.t = e
n.z = k
i.p = c
i.z = a
i.x = a
c.o = b
c.u = n
c.v = i
c.z = m
l.x = m
l.t = e
l.z = k
assert a.u.t.p.z.u.z.y.o.txt == "i"