class A:
    def __init__(self, txt: str):
        self.s: C = None
        self.w: E = None
        self.p: F = None
        self.z: E = None
        self.y: D = None
        self.txt = txt

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

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

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

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

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

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

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

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

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

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

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

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

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

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