from collections import defaultdict
import sys
input = sys.stdin.buffer.readline
sys.setrecursionlimit(10 ** 7)


N = int(input())
X = defaultdict(int)
Y = defaultdict(int)
for _ in range(N):
    a, b, t = map(int, input().split())
    if a == 0:
        X[b-t] += 1
    else:
        Y[b-t] += 1

ans = 0
for k, v in X.items():
    ans += v * Y[k]
print(ans)