while True:
s = []
N = input()
if 1 >= N or N >= 10**5:
print("Make sure to be within limit of 1 to 10**5")
break
else:
N = len(s)
count = 0
for i in range(N):
add = input()
if 1 >= add or add >= 10**9:
print("Make sure to be within limit of 1 to 10**9")
break
else:
s.append(add)
if s[i] == 7 or (s[i] + s[i+1]) / 7 == 0:
count +=1
print(count)
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