n = int(input())


def question(i):
    print("?", i)
    ans = int(input())
    return ans

def answer(i, j):
    print("Yes", i, j)

l = 1
r = n

minli = [-1 for i in range(n+1)]
maxli = [-1 for i in range(n+1)]
minli[1] = 1
maxli[1] = n-1

minli[n] = 1
maxli[n] = n-1

while abs(r-l) > 1:
    mid = (r+l)//2
    ans = question(mid)
    minli[mid] = ans
    maxli[mid] = ans
    maxli[l] = min(maxli[l], ans)
    minli[r] = max(minli[r], ans)

    reslocl = mid-l-1
    reslocr = r-mid-1

    resvall = ans - minli[l]
    resvalr = maxli[r] - ans

    if resvall <= reslocl:
        r = mid
    else:
        l = mid


answer(l,r)