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

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

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

class D:
    def __init__(self, txt: str):
        self.s: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: A = None
        self.o: B = None
        self.v: C = None
        self.q: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: E = None
        self.txt = txt

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.s: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: A = None
        self.o: B = None
        self.v: C = None
        self.q: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: E = None
        self.txt = txt

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

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

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