For problem statement at 1000-1999/1000-1099/1060-1069/1063/problemC.txt this is a correct solution, but verifier at 1000-1999/1000-1099/1060-1069/1063/verifierC.go ends with Problem C is interactive and cannot be automatically verified. can you fix the verifier? ```go
package main

import (
	"bufio"
	"fmt"
	"os"
	"strings"
)

func ask(in *bufio.Reader, out *bufio.Writer, x, y int) string {
	fmt.Fprintf(out, "%d %d\n", x, y)
	out.Flush()
	var s string
	fmt.Fscan(in, &s)
	return strings.ToLower(s)
}

func main() {
	in := bufio.NewReader(os.Stdin)
	out := bufio.NewWriter(os.Stdout)
	defer out.Flush()

	var n int
	if _, err := fmt.Fscan(in, &n); err != nil {
		return
	}

	if n <= 0 {
		fmt.Fprintln(out, "0 1 1 1")
		out.Flush()
		return
	}

	prev := ask(in, out, 0, 0)
	found := false
	var idx int

	for i := 1; i < n; i++ {
		cur := ask(in, out, i, 0)
		if cur != prev {
			found = true
			idx = i
			break
		}
	}

	if found {
		x1, y1 := idx-1, -1
		x2, y2 := idx, 1
		fmt.Fprintf(out, "%d %d %d %d\n", x1, y1, x2, y2)
	} else {
		x := n + 1
		fmt.Fprintf(out, "%d %d %d %d\n", x, 0, x, 1)
	}
	out.Flush()
}
```