#include using namespace std; #define rep(i, n) for(int i = 0; i < n; i++) #define rep2(i, x, n) for(int i = x; i <= n; i++) #define rep3(i, x, n) for(int i = x; i >= n; i--) #define each(e, v) for(auto &e: v) #define pb push_back #define eb emplace_back #define all(x) x.begin(), x.end() #define rall(x) x.rbegin(), x.rend() #define sz(x) (int)x.size() using ll = long long; using pii = pair; using pil = pair; using pli = pair; using pll = pair; const int MOD = 1000000007; //const int MOD = 998244353; const int inf = (1<<30)-1; const ll INF = (1LL<<60)-1; template bool chmax(T &x, const T &y) {return (x < y)? (x = y, true) : false;}; template bool chmin(T &x, const T &y) {return (x > y)? (x = y, true) : false;}; struct io_setup{ io_setup(){ ios_base::sync_with_stdio(false); cin.tie(NULL); cout << fixed << setprecision(15); } } io_setup; template struct Mod_Int{ int x; Mod_Int() : x(0) {} Mod_Int(long long y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {} Mod_Int &operator += (const Mod_Int &p){ if((x += p.x) >= mod) x -= mod; return *this; } Mod_Int &operator -= (const Mod_Int &p){ if((x += mod - p.x) >= mod) x -= mod; return *this; } Mod_Int &operator *= (const Mod_Int &p){ x = (int) (1LL * x * p.x % mod); return *this; } Mod_Int &operator /= (const Mod_Int &p){ *this *= p.inverse(); return *this; } Mod_Int &operator ++ () {return *this += Mod_Int(1);} Mod_Int operator ++ (int){ Mod_Int tmp = *this; ++*this; return tmp; } Mod_Int &operator -- () {return *this -= Mod_Int(1);} Mod_Int operator -- (int){ Mod_Int tmp = *this; --*this; return tmp; } Mod_Int operator - () const {return Mod_Int(-x);} Mod_Int operator + (const Mod_Int &p) const {return Mod_Int(*this) += p;} Mod_Int operator - (const Mod_Int &p) const {return Mod_Int(*this) -= p;} Mod_Int operator * (const Mod_Int &p) const {return Mod_Int(*this) *= p;} Mod_Int operator / (const Mod_Int &p) const {return Mod_Int(*this) /= p;} bool operator == (const Mod_Int &p) const {return x == p.x;} bool operator != (const Mod_Int &p) const {return x != p.x;} Mod_Int inverse() const{ assert(*this != Mod_Int(0)); return pow(mod-2); } Mod_Int pow(long long k) const{ Mod_Int now = *this, ret = 1; for(; k > 0; k >>= 1, now *= now){ if(k&1) ret *= now; } return ret; } friend ostream &operator << (ostream &os, const Mod_Int &p){ return os << p.x; } friend istream &operator >> (istream &is, Mod_Int &p){ long long a; is >> a; p = Mod_Int(a); return is; } }; using mint = Mod_Int; template struct Segment_Tree{ using F = function; int n; vector seg; const F f; const Monoid e1; Segment_Tree(const vector &v, const F &f, const Monoid &e1) : f(f), e1(e1){ int m = v.size(); n = 1; while(n < m) n <<= 1; seg.assign(2*n, e1); copy(begin(v), end(v), begin(seg)+n); for(int i = n-1; i > 0; i--) seg[i] = f(seg[2*i], seg[2*i+1]); } void change(int i, const Monoid &x){ seg[i += n] = x; while(i >>= 1){ seg[i] = f(seg[2*i], seg[2*i+1]); } } Monoid query(int l, int r) const{ Monoid L = e1, R = e1; l += n, r += n; while(l < r){ if(l&1) L = f(L, seg[l++]); if(r&1) R = f(seg[--r], R); l >>= 1, r >>= 1; } return f(L, R); } Monoid operator [] (int i) const {return seg[n+i];} template int find_subtree(int i, const C &check, const Monoid &x, Monoid &M, bool type) const{ while(i < n){ Monoid nxt = type? f(seg[2*i+type], M) : f(M, seg[2*i+type]); if(check(nxt, x)) i = 2*i+type; else M = nxt, i = 2*i+(type^1); } return i-n; } template int find_first(int l, const C &check, const Monoid &x) const{ Monoid L = e1; int a = l+n, b = n+n; while(a < b){ if(a&1){ Monoid nxt = f(L, seg[a]); if(check(nxt, x)) return find_subtree(a, check, x, L, false); L = nxt, a++; } a >>= 1, b >>= 1; } return n; } template int find_last(int r, const C &check, const Monoid &x) const{ Monoid R = e1; int a = n, b = r+n; while(a < b){ if(b&1 || a == 1){ Monoid nxt = f(seg[--b], R); if(check(nxt, x)) return find_subtree(b, check, x, R, true); R = nxt; } a >>= 1, b >>= 1; } return -1; } }; int main(){ int N; cin >> N; vector a(N); rep(i, N) cin >> a[i]; map> mp; vector s(N+1, 0); rep(i, N) s[i+1] = s[i]^a[i]; rep(i, N+1) mp[s[i]].eb(i); vector pre(N+1, 0); each(e, mp){ rep(i, sz(e.second)-1){ pre[e.second[i+1]] = e.second[i]; } } pre[N] = 0; auto f = [](mint a, mint b) {return a+b;}; Segment_Tree seg(vector(N+1, 0), f, 0); seg.change(0, 1); rep2(i, 1, N){ seg.change(i, seg.query(pre[i], i)); } cout << seg[N] << '\n'; }