#include <bits/stdc++.h>
using namespace std;
const int N = 1000040;
const int mod = 1e9 + 7;
const int mod1 = 1e9 + 7, mod2 = 1e9 + 9;
int n, a[N];
int ba1[N], ba2[N];
int sum1[N], sum2[N];
int f[N];
vector<int> t[N];
int stal[N], topl;
int star[N], topr;

void solve(int l, int r) {
	if(l >= r) {
		t[r].push_back(l - 1);
		return ;
	}
	int mid = (l + r) >> 1;
	solve(l, mid), solve(mid + 1, r);
	topl = topr = 0;
	for(int i = l; i <= mid; i++) {
		for(; topl > 0 && a[stal[topl]] >= a[i]; --topl);
		stal[++topl] = i;
	}
	for(int i = r; i > mid; i--) {
		for(; topr > 0 && a[star[topr]] >= a[i]; --topr);
		star[++topr] = i;
	}
	stal[0] = l - 1, star[0] = r + 1;
	map<pair<int, int>, int> mal, mar;
	for(int i = l - 1; i < mid; i++) mal[{sum1[i], sum2[i]}] = i;
	for(int i = mid + 1; i <= r; i++) mar[{sum1[i], sum2[i]}] = i;
	for(int i = topl, j = topr; i || j;) {
		int u = stal[i], v = star[j];
		if(!j || (i && a[u] < a[v])) {
			// stal[i - 1] + 1 -> u, mid + 1 -> v - 1
			// cout << ">>> l : " << stal[i - 1] + 1 << " " << u << " -> " << mid + 1 << " " << v - 1 << "\n";
			for(int k = stal[i - 1] + 1; k <= u; k++) {
				for(int h = a[u] + 1; h <= a[u] + 19; h++) {
					int s1 = (sum1[k - 1] + ba1[h]) % mod1;
					int s2 = (sum2[k - 1] + ba2[h]) % mod2;
					if(mar.find({s1, s2}) != mar.end()) {
						int x = mar[{s1, s2}];
						if(x <= v - 1) t[x].push_back(k - 1);
					}
				}
			}
			--i;
		}
		else {
			// u + 1 -> mid, v -> star[j - 1] - 1
			// cout << ">>> r : " << u + 1 << " " << mid << " -> " << v << " " << star[j - 1] - 1 << "\n";
			for(int k = v; k <= star[j - 1] - 1; k++) {
				for(int h = a[v] + 1; h <= a[v] + 19; h++) {
					int s1 = (sum1[k] - ba1[h] + mod1) % mod1;
					int s2 = (sum2[k] - ba2[h] + mod2) % mod2;
					if(mal.find({s1, s2}) != mal.end()) {
						int x = mal[{s1, s2}];
						if(x >= u) t[k].push_back(x);
					}
				}
			}
			--j;
		}
	}
}
int main() {
	ios::sync_with_stdio(0); cin.tie(nullptr);
	cin >> n;
	for(int i = 1; i <= n; i++) cin >> a[i];
	ba1[0] = ba1[0] = 1;
	for(int i = 1; i <= 1000020; i++) {
		ba1[i] = 1ll * ba1[i - 1] * 2 % mod1;
		ba2[i] = 1ll * ba2[i - 1] * 2 % mod2;
	}
	for(int i = 1; i <= n; i++) {
		sum1[i] = (sum1[i - 1] + ba1[a[i]]) % mod1;
		sum2[i] = (sum2[i - 1] + ba2[a[i]]) % mod2;
	}
	solve(1, n);
	f[0] = 1;
	for(int i = 1; i <= n; i++) {
		sort(t[i].begin(), t[i].end());
		t[i].resize(unique(t[i].begin(), t[i].end()) - t[i].begin());
		// for(auto v : t[i]) cout << v + 1 << " " << i << "\n";
		for(auto v : t[i]) f[i] = (f[i] + f[v]) % mod;
	}
	cout << f[n] << "\n";
	return 0;
}