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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.q: D = None
        self.r: G = None
        self.txt = txt

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

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

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.q: D = None
        self.r: G = None
        self.txt = txt

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

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

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