#include<bits/stdc++.h>
using std::cin;
using std::cout;
using ll = long long;
const ll mod = 986854057502126921;
const int N = 300005;
const int M = 1e6 + 100;
int n;
ll pw[M];
ll a[N], s[N];
std::unordered_map<ll, int> map(N * 2);

int st[20][N];
int max(int x, int y) {
	return a[x] < a[y] ? x : y;
}
int qmax(int l, int r) {
	const int lg = std::__lg(r - l + 1);
	return max(st[lg][l], st[lg][r - (1 << lg) + 1]);
}
std::vector<int> e[N];

const int V = 19;
void solve(int l, int r) {
	if(l > r) return ;
	int m = qmax(l, r);
	const int vm = a[m];
	solve(l, m - 1);
	solve(m + 1, r);
	if(m - l < r - m) {
		for(int i = l;i <= m;++i) {
			for(int p = vm;p < vm + V;++p) {
				ll sum = s[i - 1] + pw[p];
				if(sum >= mod) sum -= mod;
				auto iter = map.find(sum);
				if(iter != map.end()) {
					if(int p = iter -> second;m <= p && p <= r) {
						e[p].push_back(i - 1);
					}
				}
			}
		}
	} else {
		for(int i = m;i <= r;++i) {
			for(int p = vm;p < vm + V;++p) {
				ll sum = s[i] - pw[p];
				if(sum < 0) sum += mod;
				auto iter = map.find(sum);
				if(iter != map.end()) {
					if(int p = iter -> second;l - 1 <= p && p < m) {
						e[i].push_back(p);
					}
				}
			}
		}
	}
}
void pengbo() {
	const int mod = 1e9 + 7;
	std::vector<int> dp(n + 1);
	dp[0] = 1;
	for(int i = 1;i <= n;++i) {
		for(int z : e[i]) {
			dp[i] = (dp[i] + dp[z]) % mod;
		}
	}
	cout << dp[n] << '\n';
}
int main() {
	std::ios::sync_with_stdio(false), cin.tie(0);
	*pw = 1;
	for(int i = 1;i < M;++i) {
		pw[i] = pw[i - 1] * 2 % mod;
	}
	cin >> n;
	map[0] = 0;
	for(int i = 1;i <= n;++i) {
		st[0][i] = i;
		cin >> a[i];
		s[i] = (s[i - 1] + pw[a[i]]) % mod;
		map[s[i]] = i;
	}
	for(int i = 1;i < 20;++i) {
		for(int j = 1;j + (1 << i) - 1 <= n;++j) {
			st[i][j] = max(st[i - 1][j], st[i - 1][j + (1 << (i - 1))]);
		}
	}
	solve(1, n);
	pengbo();
}