// (t-Ti, Bi) == (Bj, t-Tj)
// |t-Ti+Bi| == |Bj+t-Tj|
// |t+Bi-Ti| == |t+Bj-Tj|
package main

import . "fmt"
import . "os"
import bf "bufio"

func main() {
	rd:=bf.NewReader(Stdin)
	var n int
	Fscan(rd,&n)
	red := map[int]int{}
	blue := []int{}
	for i := 0; i < n; i++ {
		var a,b,t int
		Fscan(rd,&a,&b,&t)
		if a==0 {
			red[b-t]++
		} else {
			blue = append(blue, b-t)
		}
	}
	ans := 0
	for _, c := range blue {
		ans += red[c]
	}
	Println(ans)
}