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

class B:
    def __init__(self, txt: str):
        self.v: F = None
        self.z: F = None
        self.o: A = None
        self.w: E = None
        self.y: B = None
        self.p: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: A = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.v: F = None
        self.z: F = None
        self.o: A = None
        self.w: E = None
        self.y: B = None
        self.p: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: A = None
        self.txt = txt

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

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

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

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