from collections import defaultdict
n=int(input())
red=defaultdict(int)
blue=[]
for _ in range(n):
    a,b,t=map(int,input().split())
    if a==0:
        red[b-t]+=1
    else:
        blue.append(b-t)
ans=0
for i in blue:
    ans+=red[i]
print(ans)