```go
package main

import "fmt"

func main() {
	var x1, y1, x2, y2, x3, y3 int
	fmt.Scan(&x1, &y1)
	fmt.Scan(&x2, &y2)
	fmt.Scan(&x3, &y3)

	if (x1 == x2 && x2 == x3) || (y1 == y2 && y2 == y3) {
		fmt.Println(1)
		return
	}

	xs := []int{x1, x2, x3}
	ys := []int{y1, y2, y3}

	for i := 0; i < 3; i++ {
		for j := i + 1; j < 3; j++ {
			k := 3 - i - j
			if xs[i] == xs[j] {
				miny, maxy := ys[i], ys[j]
				if miny > maxy {
					miny, maxy = maxy, miny
				}
				if ys[k] <= miny || ys[k] >= maxy {
					fmt.Println(2)
					return
				}
			}
			if ys[i] == ys[j] {
				minx, maxx := xs[i], xs[j]
				if minx > maxx {
					minx, maxx = maxx, minx
				}
				if xs[k] <= minx || xs[k] >= maxx {
					fmt.Println(2)
					return
				}
			}
		}
	}

	fmt.Println(3)
}
```