import sys
readline = sys.stdin.readline
write = sys.stdout.write
flush = sys.stdout.flush


# クエリ: "? x1 x2" を出力
def query(x1):
    write("? %d\n" % (x1))
    flush()
    # ジャッジから返される値を取得
    return int(readline())

# 回答: "! x" を出力
def answer(x1,x2):
    write("! %d %d\n" % (x1,x2))
    flush()
    # 即時終了
    exit(0)

N = int(input())
if N<=20:
    L = [0]*N
    for i in range(1,N+1):
        l = query(i)
        L[i-1]=l
    for i in range(N):
        for j in range(i+2,N,2):
            if N-1>j-i>=N/2 and L[j]-L[i]==(j-i)/2:
                answer(i+1,j+1)

T2 = query(2)
if T2==1:
    answer(3,N)
B2 = query(N-2)
if B2==N/2-1:
    answer(1,N-2)
if (T2==2 and B2==N/2) or (T2==0 and B2==N/2-2) :
    answer(3,N-2)

def is_ok(m):
    v = query(m)
    if v==m/2:
        if m<N/2:
            answer(m+1,N)
        else:
            answer(1,m)
    return v>m/2

def meguru_bisect(ng, ok):
    while (abs(ok - ng) > 1):
        mid = (ok + ng) // 2
        if is_ok(mid):
            ok = mid
        else:
            ng = mid
    return ok

meguru_bisect(N,1)