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

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

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

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

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

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

k = A("k")
j = B("j")
i = C("i")
h = D("h")
c = E("c")
g = F("g")

k.y = g
k.q = c
k.t = c
k.u = c
k.o = i
k.x = i
j.t = g
j.x = i
j.y = c
j.u = c
i.r = g
i.v = j
i.o = j
h.y = k
h.v = k
h.r = g
h.s = g
h.q = i
c.v = i
c.u = i
c.w = j
c.x = j
g.t = j
g.x = k
g.u = i
g.v = i
g.r = i
g.p = c
assert g.p.x.x.txt == "
class A:
    def __init__(self, txt: str):
        self.y: F = None
        self.q: E = None
        self.t: E = None
        self.u: E = None
        self.o: C = None
        self.x: C = None
        self.txt = txt

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

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

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

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

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

k = A("k")
j = B("j")
i = C("i")
h = D("h")
c = E("c")
g = F("g")

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