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

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

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

class D:
    def __init__(self, txt: str):
        self.q: B = None
        self.v: E = None
        self.s: E = None
        self.x: B = None
        self.u: F = None
        self.z: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: C = None
        self.u: C = None
        self.s: C = None
        self.y: D = None
        self.r: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: F = None
        self.x: D = None
        self.z: B = None
        self.s: B = None
        self.o: C = None
        self.y: B = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.q: B = None
        self.v: E = None
        self.s: E = None
        self.x: B = None
        self.u: F = None
        self.z: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: C = None
        self.u: C = None
        self.s: C = None
        self.y: D = None
        self.r: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: F = None
        self.x: D = None
        self.z: B = None
        self.s: B = None
        self.o: C = None
        self.y: B = None
        self.txt = txt

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

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