class A:
    def __init__(self, txt: str):
        self.o: F = None
        self.v: F = None
        self.s: B = None
        self.u: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.v: F = None
        self.q: B = None
        self.y: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.y: D = None
        self.p: E = None
        self.s: A = None
        self.x: D = None
        self.r: D = None
        self.txt = txt

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

g = A("g")
m = B("m")
h = C("h")
c = D("c")
j = E("j")
f = F("f")
d = E("d")
l = B("l")
i = D("i")

g.o = f
g.v = f
g.u = f
g.s = m
m.v = f
m.q = l
m.y = g
h.r = d
c.u = f
c.o = f
c.x = f
j.y = i
j.p = d
j.s = g
j.x = c
j.r = c
f.r = j
f.s = i
d.y = c
d.r = c
d.p = j
d.s = g
d.x = i
l.v = f
l.q = m
l.y = g
i.u = f
i.o = f
i.x = f
assert j.p.s.v.r.txt == "
class A:
    def __init__(self, txt: str):
        self.o: F = None
        self.v: F = None
        self.s: B = None
        self.u: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.v: F = None
        self.q: B = None
        self.y: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.y: D = None
        self.p: E = None
        self.s: A = None
        self.x: D = None
        self.r: D = None
        self.txt = txt

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

g = A("g")
m = B("m")
h = C("h")
c = D("c")
j = E("j")
f = F("f")
d = E("d")
l = B("l")
i = D("i")

g.o = f
g.v = f
g.u = f
g.s = m
m.v = f
m.q = l
m.y = g
h.r = d
c.u = f
c.o = f
c.x = f
j.y = i
j.p = d
j.s = g
j.x = c
j.r = c
f.r = j
f.s = i
d.y = c
d.r = c
d.p = j
d.s = g
d.x = i
l.v = f
l.q = m
l.y = g
i.u = f
i.o = f
i.x = f
assert j.p.s.v.r.txt == "j"