For problem statement at 1000-1999/1400-1499/1400-1409/1406/problemE.txt this is a correct solution, but verifier at 1000-1999/1400-1499/1400-1409/1406/verifierE.go ends with Problem E is interactive and cannot be automatically verified. can you fix the verifier? package main

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

func ask(in *bufio.Reader, out *bufio.Writer, op string, a int) int {
	fmt.Fprintf(out, "%s %d\n", op, a)
	out.Flush()
	var res int
	if _, err := fmt.Fscan(in, &res); err != nil {
		os.Exit(0)
	}
	if res == -1 {
		os.Exit(0)
	}
	return res
}

func answer(out *bufio.Writer, x int) {
	fmt.Fprintf(out, "C %d\n", x)
	out.Flush()
}

func main() {
	in := bufio.NewReaderSize(os.Stdin, 1<<20)
	out := bufio.NewWriterSize(os.Stdout, 1<<20)
	defer out.Flush()

	var n int
	fmt.Fscan(in, &n)

	comp := make([]bool, n+1)
	primes := make([]int, 0)
	for i := 2; i <= n; i++ {
		if !comp[i] {
			primes = append(primes, i)
			if i*i <= n {
				for j := i * i; j <= n; j += i {
					comp[j] = true
				}
			}
		}
	}

	split := 0
	for split < len(primes) && primes[split]*primes[split] <= n {
		split++
	}

	ans := 1
	remain := n

	for i := 0; i < split; i++ {
		p := primes[i]
		b := ask(in, out, "B", p)
		a := ask(in, out, "A", p)
		if a > 0 {
			cur := p
			for cur <= n/p {
				next := cur * p
				if ask(in, out, "A", next) > 0 {
					cur = next
				} else {
					break
				}
			}
			ans *= cur
			remain -= b - 1
		} else {
			remain -= b
		}
	}

	block := 100
	for i := split; i < len(primes); i += block {
		end := i + block
		if end > len(primes) {
			end = len(primes)
		}
		for j := i; j < end; j++ {
			remain -= ask(in, out, "B", primes[j])
		}
		real := ask(in, out, "A", 1)
		if real != remain {
			for j := i; j < end; j++ {
				if ask(in, out, "A", primes[j]) > 0 {
					ans *= primes[j]
					answer(out, ans)
					return
				}
			}
		}
	}

	answer(out, ans)
}