N = int(input())
red = []
blue = []
for _ in range(N):
    a,b,t = map(int,input().split())
    if a==0:
        red.append(b-t)
    else:
        blue.append(b-t)
from collections import Counter
c = Counter(red)
c_b = Counter(blue)
ans = 0
for key,value in c.items():
    ans += value*c_b[key]
print(ans)