N = int(input())

R = {}
B = {}

for i in range(N):
    c,a,b = map(int,input().split())
    if c:
        if a-b not in R:
            R[a-b] = 0
        R[a-b] += 1
    else:
        if a-b not in B:
            B[a-b] = 0
        B[a-b] += 1

ans = 0
for k,v in R.items():
    if k in B:
        ans += R[k] * B[k]
print(ans)