n = int(input())
l = 0
r = n + 1
l_ = 0
r_ = n

while r - l > 1:
    mid = (l + r) // 2
    print("? {}".format(mid), flush=True)
    x = int(input())
    if mid - l >= x - l_:
        l = mid
        l_ = x
    else:
        r = mid
        r_ = x

print("Yes {} {}".format(l, r), flush=True)