n = int(input())


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

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


ok = 1
ng = n


while abs(ok-ng) > 1:
    mid = (ok+ng)//2

    ans = question(mid)
    if ans >= mid:
        ok = mid
    else:
        ng = mid

answer(ok, ok+1)