n, k = map(int, input().split()) lo, hi = 1, n ans = n while lo <= hi: mid = (lo + hi) // 2 q = n // mid r = n % mid total = r * (q + 1) * (q + 2) // 2 + (mid — r) * q * (q + 1) // 2 if total <= k: ans = mid hi = mid — 1 else: lo = mid + 1 print(ans)