package main

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

func main() {
	r := bufio.NewReader(os.Stdin)
	w := bufio.NewWriter(os.Stdout)
	defer w.Flush()
	var N int
	fmt.Fscan(r, &N)
	p := make([]int, N-1)
	for i := 0; i < N-1; i++ {
		fmt.Fprintf(w, "? %d %d\n", i, N-1)
		w.Flush()
		var x int
		fmt.Fscan(r, &x)
		if x < 0 {
			return
		}
		p[i] = x
	}
	var cand []int
	for L := 1; L <= 9; L++ {
		ok := true
		for i := 0; i < N-1; i++ {
			if p[i]%L != 0 {
				ok = false
				break
			}
			di := p[i] / L
			if di < 0 || di > 9 {
				ok = false
				break
			}
		}
		if ok {
			cand = append(cand, L)
		}
	}
	if len(cand) == 0 {
		fmt.Fprintf(w, "! -1\n")
		return
	}
	if len(cand) > 1 && N > 2 {
		fmt.Fprintf(w, "? 0 1\n")
		w.Flush()
		var p01 int
		fmt.Fscan(r, &p01)
		if p01 < 0 {
			return
		}
		var nc []int
		for _, L := range cand {
			if p[0]%L != 0 || p[1]%L != 0 {
				continue
			}
			d0 := p[0] / L
			d1 := p[1] / L
			if d0*d1 == p01 {
				nc = append(nc, L)
			}
		}
		cand = nc
	}
	if len(cand) != 1 {
		fmt.Fprintf(w, "! -1\n")
		return
	}
	L := cand[0]
	d := make([]int, N)
	d[N-1] = L
	for i := 0; i < N-1; i++ {
		d[i] = p[i] / L
	}
	ans := 0
	for i := N - 1; i >= 0; i-- {
		ans = ans*10 + d[i]
	}
	fmt.Fprintf(w, "! %d\n", ans)
}