class A:
    def __init__(self, txt: str):
        self.z: C = None
        self.q: F = None
        self.v: C = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.u: G = None
        self.p: F = None
        self.y: B = None
        self.q: A = None
        self.x: C = None
        self.o: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.x: D = None
        self.s: G = None
        self.r: B = None
        self.y: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.o: F = None
        self.txt = txt

g = A("g")
b = B("b")
m = C("m")
d = D("d")
c = E("c")
f = F("f")
l = G("l")
a = C("a")
e = B("e")

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

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

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

class D:
    def __init__(self, txt: str):
        self.u: G = None
        self.p: F = None
        self.y: B = None
        self.q: A = None
        self.x: C = None
        self.o: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.x: D = None
        self.s: G = None
        self.r: B = None
        self.y: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.o: F = None
        self.txt = txt

g = A("g")
b = B("b")
m = C("m")
d = D("d")
c = E("c")
f = F("f")
l = G("l")
a = C("a")
e = B("e")

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