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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.y: D = None
        self.w: A = None
        self.u: D = None
        self.p: C = None
        self.r: B = None
        self.txt = txt

j = A("j")
m = B("m")
k = C("k")
b = D("b")
c = E("c")
g = F("g")
l = F("l")

j.s = c
j.o = c
j.r = m
j.x = b
m.x = c
k.v = b
k.u = j
b.q = g
b.x = k
b.v = j
b.t = m
b.o = c
b.w = c
c.t = b
c.q = j
c.u = j
c.o = k
c.v = m
c.x = m
g.y = b
g.u = b
g.w = j
g.p = k
g.r = m
l.y = b
l.u = b
l.w = j
l.p = k
l.r = m
assert b.x.v.t.txt == "
class A:
    def __init__(self, txt: str):
        self.s: E = None
        self.o: E = None
        self.r: B = None
        self.x: D = None
        self.txt = txt

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.y: D = None
        self.w: A = None
        self.u: D = None
        self.p: C = None
        self.r: B = None
        self.txt = txt

j = A("j")
m = B("m")
k = C("k")
b = D("b")
c = E("c")
g = F("g")
l = F("l")

j.s = c
j.o = c
j.r = m
j.x = b
m.x = c
k.v = b
k.u = j
b.q = g
b.x = k
b.v = j
b.t = m
b.o = c
b.w = c
c.t = b
c.q = j
c.u = j
c.o = k
c.v = m
c.x = m
g.y = b
g.u = b
g.w = j
g.p = k
g.r = m
l.y = b
l.u = b
l.w = j
l.p = k
l.r = m
assert b.x.v.t.txt == "m"