For problem statement at 0-999/800-899/800-809/804/problemA.txt this is a correct solution, but verifier at 0-999/800-899/800-809/804/verifierA.go ends with All tests passed can you fix the verifier? package main

import "fmt"

func main() {
	var n int
	if _, err := fmt.Scan(&n); err == nil {
		fmt.Println((n - 1) / 2)
	}
}