class A:
    def __init__(self, txt: str):
        self.x: A = None
        self.r: F = None
        self.y: E = None
        self.o: A = None
        self.v: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: E = None
        self.o: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.w: C = None
        self.u: F = None
        self.txt = txt

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

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

i = A("i")
l = B("l")
m = C("m")
k = D("k")
h = E("h")
a = F("a")
b = A("b")
n = C("n")
g = C("g")
d = F("d")

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

class B:
    def __init__(self, txt: str):
        self.t: E = None
        self.o: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.w: C = None
        self.u: F = None
        self.txt = txt

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

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

i = A("i")
l = B("l")
m = C("m")
k = D("k")
h = E("h")
a = F("a")
b = A("b")
n = C("n")
g = C("g")
d = F("d")

i.x = b
i.o = b
i.r = a
i.v = a
i.y = h
l.t = h
l.o = i
m.x = b
m.y = b
m.o = d
m.s = l
m.r = k
k.w = g
k.u = a
h.t = l
h.v = d
h.q = d
h.o = i
h.r = b
h.y = k
a.o = l
a.x = m
b.x = i
b.o = i
b.r = a
b.v = a
b.y = h
n.x = i
n.y = i
n.o = d
n.s = l
n.r = k
g.x = b
g.y = b
g.o = a
g.s = l
g.r = k
d.o = l
d.x = m
assert m.y.y.r.v.x.y.y.txt == "h"