def ask(x, y):
    print("?", x + 1, y + 1, flush=True)
    return int(input()) - 1

def judge(x):
    print("!", x + 1)
    exit()

n = int(input())
A = [i for i in range(n)]
vs = [-1] * n
while len(A) >= 2:
    B = []
    while len(A) >= 2:
        x = A.pop()
        y = A.pop()
        z = ask(x, y)
        B.append(z)
        if x == z:
            vs[y] = x
        else:
            vs[x] = y
            
    A += B

x = A[0]
A = []
for i in range(n):
    if vs[i] == x:
        A.append(i)

while len(A) >= 2:
    B = []
    while len(A) >= 2:
        x = A.pop()
        y = A.pop()
        z = ask(x, y)
        B.append(z)
        if x == z:
            vs[y] = x
        else:
            vs[x] = y
            
    A += B
judge(A[0])