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

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

class C:
    def __init__(self, txt: str):
        self.u: E = None
        self.o: E = None
        self.p: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.p: B = None
        self.w: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: E = None
        self.z: G = None
        self.s: B = None
        self.y: C = None
        self.p: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: B = None
        self.r: A = None
        self.o: D = None
        self.z: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: A = None
        self.q: D = None
        self.p: A = None
        self.z: D = None
        self.w: A = None
        self.txt = txt

f = A("f")
n = B("n")
d = C("d")
b = D("b")
i = E("i")
a = F("a")
j = G("j")
g = B("g")
c = E("c")
l = F("l")

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

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

class C:
    def __init__(self, txt: str):
        self.u: E = None
        self.o: E = None
        self.p: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.p: B = None
        self.w: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: E = None
        self.z: G = None
        self.s: B = None
        self.y: C = None
        self.p: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: B = None
        self.r: A = None
        self.o: D = None
        self.z: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: A = None
        self.q: D = None
        self.p: A = None
        self.z: D = None
        self.w: A = None
        self.txt = txt

f = A("f")
n = B("n")
d = C("d")
b = D("b")
i = E("i")
a = F("a")
j = G("j")
g = B("g")
c = E("c")
l = F("l")

f.u = i
f.q = g
f.t = j
f.r = d
n.r = c
n.z = i
n.w = a
n.y = b
n.x = b
d.u = c
d.o = i
d.p = f
b.p = g
b.w = f
i.o = c
i.z = j
i.p = j
i.s = g
i.y = d
a.x = g
a.r = f
a.o = b
a.z = b
j.x = f
j.p = f
j.w = f
j.q = b
j.z = b
g.r = i
g.z = c
g.w = a
g.y = b
g.x = b
c.o = i
c.z = j
c.p = j
c.s = n
c.y = d
l.x = n
l.r = f
l.o = b
l.z = b
assert i.z.z.w.u.o.txt == "c"