N=int(input())
#print(N)
C=0
if C==0:
    J=[i+1 for i in range(N)]
    #print(len(J),J[0],J[-1])
    for i in range(10):
        W=[]
        if len(J)%2==1:
            W.append(J[-1])
        for j in range(len(J)//2):
            #print(W,J)
            print("?",J[j*2],J[j*2+1],flush=True)
            n=int(input())
            W.append(n)
        #print("i",i,J,W)
        if len(W)==1:
            C=W[0]
            break
        else:
            J=W

if C!=0:
    #print(C)
    J=[]
    for i in range(1,N+1):
        if i==C:
            pass
        else:
            J.append(i)
    for i in range(10):
        W=[]
        if len(J)%2==1:
            W.append(J[-1])
        for j in range(len(J)//2):
            print("?",J[j*2],J[j*2+1],flush=True)
            n=int(input())
            W.append(n)
        #print("I",J,W)
        if len(W)==1:
            print("!",W[0],flush=True)
            exit()
        else:
            J=W