import sys

# sys.setrecursionlimit(1000005)
# sys.set_int_max_str_digits(200005)
int1 = lambda x: int(x)-1
pDB = lambda *x: print(*x, end="\n", file=sys.stderr)
p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr)
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()

# dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
# inf = -1-(-1 << 31)
inf = -1-(-1 << 63)
# md = 10**9+7
md = 998244353

# at t sec
# (Bi,t-Ti)==(t-Tj,Bj)
# Bi==t-Tj,t-Ti==Bj
# Bi+Tj==t,t==Bj+Ti
# Bi+Tj==Bj+Ti
# Bi-Ti==Bj-Tj

from collections import Counter

n=II()
cnt=Counter()
bt=[]
ans=0
for _ in range(n):
    a,b,t=LI()
    if a:
        cnt[b-t]+=1
    else:
        bt.append(b-t)
        
for v in bt:ans+=cnt[v]
print(ans)