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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.q: C = None
        self.t: G = None
        self.x: G = None
        self.txt = txt

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

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

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.q: C = None
        self.t: G = None
        self.x: G = None
        self.txt = txt

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

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

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