E题线性基然后直接暴力就行吧 ```c++ ll c[60], k, a, ans; int cnt[60]; void add(ll a) { per (i, 59, 0) if (a >> i & 1) { if (!c[i]) { c[i] = a; break; } else a ^= c[i]; } } int main() { IOS; cin >> n >> k; rep (i, 1, n) cin >> a, add(a); rep (i, 0, 59) cnt[i] = cnt[i - 1] + (c[i] != 0); per (i, 59, 1) if (!(k >> i & 1) && c[i]) ans += (1ll << cnt[i - 1]); if (!(k & 1) && c[0]) ++ans; cout << ans; return 0; } ```