exit(0)
else:
pass
if ([{'z', 'a'}, {'b', 'y'}, {'c', 'x'}, {'d', 'w'}] == return_val):
print(return_val)
flag+=1
exit(0)
else:
pass
if ([{'q', 'p'}, {'w', 'o'}, {'e', 'i'}, {'r', 'u'}] == return_val):
print(return_val)
flag+=1
exit(0)
else:
pass
if ([{'a', 'l'}, {'s', 'k'}, {'j', 'd'}, {'f', 'h'}] == return_val):
print(return_val)
flag+=1
exit(0)
else:
pass
if(flag==0):
print('0')
keys = list(map(str,input().split()))
values =list(map(str,input().split()))
g = {}
for key, value in zip(keys, values):
g[key] = value
graph = Graph(g)
test_case1(graph.edges())
