n = int(input()) cnts = [-1] * n l, r = 1, n + 1 for _ in range(10): m = (l + r) // 2 print(f"? {m}", flush=True) res = int(input()) if cnts[res] != -1: print(f"Yes {cnts[res]} {m}") exit() cnts[res] = m if res < m: r = m else: l = m print("No")