#include <bits/stdc++.h>

#define int long long
#define pii pair<int, int>

using namespace std;

const int N = 3e5 + 5, M = 1e6 + 40, MOD = 1e9 + 7;
const int hashmod = (int) 1e18 - 111;

int n, a[N], p[M], dp[N], hsh[N], np[N];

inline  void add(int &x, int y){
    x += y;
    while(x >= MOD) x -= MOD;
}

set<pii> upd;
map<int, int> f;
set<int> s;
void dnc(int l, int r){
    if(l == r){ return add(dp[r], dp[l - 1]), void(); }
    int mid = (l + r) / 2;
    dnc(l, mid);
    for(int i = mid; i >= l; i--){
        int x = a[i];
        while(!s.empty() && s.find(x) != s.end()){ s.erase(x++); }
        s.insert(x);
        np[i] = max((i < mid ? np[i + 1] : 0LL), x + 1);
        hsh[i] = (i < mid ? hsh[i + 1] : 0LL) + p[a[i]];
        hsh[i] %= hashmod;
    }
    s.clear();
    for(int i = mid + 1; i <= r; i++){
        int x = a[i];
        while(!s.empty() && s.find(x) != s.end()){ s.erase(x++); }
        s.insert(x);
        np[i] = max((i > mid + 1 ? np[i - 1] : 0LL), x + 1);
        hsh[i] = (i > mid + 1 ? hsh[i - 1] : 0LL) + p[a[i]];
        hsh[i] %= hashmod;
    }
    s.clear();
    for(int i = mid + 1; i <= r; i++) f[hsh[i]] = i;
    f[0] = mid;
    for(int i = mid; i >= l; i--){
        int wanted = (p[np[i]] + hashmod - hsh[i]) % hashmod;
        if(f.count(wanted) && f[wanted] - i > 0) upd.insert({i, f[wanted]});
    }
    f.clear();
    for(int i = l; i <= mid; i++) f[hsh[i]] = i;
    f[0] = mid + 1;
    for(int i = mid + 1; i <= r; i++){
        int wanted = (p[np[i]] + hashmod - hsh[i]) % hashmod;
        if(f.count(wanted) && i - f[wanted] > 0) upd.insert({f[wanted], i});
    }
    f.clear();
    for(pii x: upd){
        add(dp[x.second], dp[x.first - 1]);
    }
    upd.clear();
    dnc(mid + 1, r);
}


signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    p[0] = dp[0] = 1;
    for(int i = 1; i < M; i++){
        p[i] = p[i - 1] * 2 % hashmod;
    }
    cin >> n;
    for(int i = 1; i <= n; i++){
        cin >> a[i];
    }
    dnc(1, n);
    cout << dp[n] << '\n';
}