#!/usr/bin/env python
 
# read dominoes
N = 7
dominoes = [[0] * N for _ in range(N)]
for _ in range(int(input())):
    i, j = map(int, input().split())
    dominoes[j][i] = dominoes[i][j] = dominoes[i][j] + 1
 
# count "friendly" pairs
npairs = 0
for i in range(N):  # for each domino i:j where i <= j
    for j in range(i, N):
        n = dominoes[i][j]
        if n:
            # {n \choose 2} pairs with itself
            npairs += n * (n - 1) // 2
            for k in range(i+1, N):      # top-down
                npairs += dominoes[k][j] * n
            if i != j:  # don't count twice 
                for k in range(j+1, N):      # left-right
                    npairs += dominoes[i][k] * n
print(npairs)

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NQoxIDIKMiAzCjMgMQo0IDMKNCAz

5
1 2
2 3
3 1
4 3
4 3