import sys
def input(): return sys.stdin.readline().strip()
def mapint(): return list(map(int, input().split()))
sys.setrecursionlimit(10**9)

N = int(input())

from collections import defaultdict
remains = list(range(1, N+1))
lost_by = defaultdict(list)

def f(remains):
    while(len(remains)!=1):
        nx_remains = []
        if(len(remains)%2==1):
            nx_remains.append(remains[-1])
        for i in range(0, len(remains)-1, 2):
            a = remains[i]
            b = remains[i+1]
            print(f"? {a} {b}", flush=True)
            ret = int(input())
            if(ret==a):
                nx_remains.append(a)
                lost_by[a].append(b)
            else:
                nx_remains.append(b)
                lost_by[b].append(a)
        remains = nx_remains
    return remains[0]
    
first = f(remains)
print(f"! {f(lost_by[first])}")