Digit Pairs

n=int(input())

a=[(((ord(max(i))-ord('0'))*11+(ord(min(i))-ord('0'))*7)%100)//10 for i in input().split()]

l=[0]*10

for i in range(n-2):

    for j in a[i+2::2]:

        l[j]+=(j==a[i])

n=0

for i in l:

    n+=(i>0)+(i>1)

print(n)