#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int MAX_N = 300000 + 5;
const int MAX_M = 1 << 20;
const ll P = 3270674594228402513ll;
const int MOD = 1000000000 + 7;

mt19937_64 rnd64(chrono::steady_clock::now().time_since_epoch().count());

ll coef[MAX_M], sumc[MAX_M];

inline ll add(ll a, ll b) {return a + b < P ? a + b : a + b - P;}

void init() {
    coef[0] = 1;
    sumc[0] = 1;
    for (int i = 1; i < MAX_M; i ++) {
        coef[i] = add(coef[i - 1], coef[i - 1]);
        coef[i] = add(coef[i - 1], coef[i]);
        sumc[i] = add(sumc[i - 1], coef[i]);
    }
}

int N, a[MAX_N], f[MAX_N];
vector <int> lp[MAX_N];

void solve(int l, int r) {
    if (l == r) {
        lp[l].emplace_back(l);
        return ;
    }
    int mid = l + r >> 1;
    solve(l, mid); solve(mid + 1, r);
    set <int> s;
    map <int, int> pre, suf;
    ll hash = 0;
    auto ins = [&](int x) -> void {
        while (s.count(x)) {
            hash = add(hash, P - coef[x]);
            s.erase(x); x ++;
        }
        s.insert(x);
        hash = add(hash, coef[x]);
    };
    for (int i = mid; i >= l; i --) {
        ins(a[i]);
        pre[hash] = i;
    }
    s.clear(); hash = 0;
    for (int i = mid + 1; i <= r; i ++) {
        ins(a[i]);
        suf[hash] = i;
        int lowbit = *s.begin(), highbit = *s.rbegin();
        ll tmp = add(sumc[highbit], P - sumc[lowbit]);
        tmp = add(tmp, P - hash);
        tmp = add(tmp, coef[lowbit]);
        tmp = add(tmp, coef[lowbit]);
        if (pre.count(tmp)) {
            lp[i].emplace_back(pre[tmp]);
        }
    }
    s.clear(); hash = 0;
    for (int i = mid; i >= l; i --) {
        ins(a[i]);
        int lowbit = *s.begin(), highbit = *s.rbegin();
        ll tmp = add(sumc[highbit], P - sumc[lowbit]);
        tmp = add(tmp, P - hash);
        tmp = add(tmp, coef[lowbit]);
        tmp = add(tmp, coef[lowbit]);
        if (tmp != hash && suf.count(tmp)) {
            lp[suf[tmp]].emplace_back(i);
        }
    }
}

int main() {
    init();
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    
    cin >> N;
    for (int i = 1; i <= N; i ++) {
        cin >> a[i];
    }
    solve(1, N);
    f[0] = 1;
    for (int i = 1; i <= N; i ++) {
        for (auto j : lp[i]) {
            f[i] += f[j - 1];
            (f[i] >= MOD && (f[i] -= MOD));
        }
    }
    cout << f[N] << '\n';
    
    return 0;
}