class A:
    def __init__(self, txt: str):
        self.x: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: E = None
        self.v: A = None
        self.r: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: A = None
        self.z: E = None
        self.s: B = None
        self.v: B = None
        self.t: G = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.x: B = None
        self.t: B = None
        self.r: B = None
        self.w: F = None
        self.o: G = None
        self.y: E = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.t: E = None
        self.v: A = None
        self.r: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: A = None
        self.z: E = None
        self.s: B = None
        self.v: B = None
        self.t: G = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.x: B = None
        self.t: B = None
        self.r: B = None
        self.w: F = None
        self.o: G = None
        self.y: E = None
        self.txt = txt

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

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