#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/hash_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

typedef unsigned long long ull;

mt19937_64 rng(time(0));

const int N = 3e5 + 5, M = 1e6 + 30 + 5, Mod = 1e9 + 7;
int n = 0, m = 1000030, a[N] = {}, f[N] = {}, p = 0, q = 0, b[M] = {};
vector<int> v;
ull s[M] = {}, t[M] = {}, h = 0;
cc_hash_table<ull, int> g, g1, g2;

inline void calc(int x){
	b[x] ^= 1, h ^= s[x], v.push_back(x);
	if(!b[x]){
		if(x == p) p ++;
		calc(x + 1);
	}
	else{
		if(p == -1 && q == -1) p = q = x;
		else p = min(p, x), q = max(q, x);
	}
}

inline void cdq(int l, int r){
	if(r - l == 1) return;
	int o = (l + r) / 2;
	cdq(l, o);
	
	g.clear(), g1.clear(), g2.clear();
	
	for(int x : v) b[x] = 0;
	v.clear(), h = 0, p = q = -1;
	
	for(int i = o - 1 ; i >= l ; i --){
		calc(a[i]);
		g1[h] = (g1[h] + f[i]) % Mod, g2[h ^ t[p] ^ t[q]] = (g2[h ^ t[p] ^ t[q]] + f[i]) % Mod;
		if(p == q) g[p] = (g[p] + f[i]) % Mod, f[o] = (f[o] + f[i]) % Mod;
	}
	
	for(int x : v) b[x] = 0;
	v.clear(), h = 0, p = q = -1;
	
	for(int i = o + 1 ; i < r ; i ++){
		calc(a[i] - 1);
		f[i] = (f[i] + g1[h ^ t[p] ^ t[q]]) % Mod, f[i] = (f[i] + g2[h]) % Mod;
		if(p == q) f[i] = (f[i] + Mod - g[p]) % Mod;
	}
	
	cdq(o, r);
}

int main(){
	for(int i = 0 ; i < m ; i ++){
		s[i] = rng(), t[i] ^= s[i];
		t[i + 1] = t[i];
	}
	scanf("%d", &n);
	for(int i = 0 ; i < n ; i ++) scanf("%d", &a[n]);
	f[0] = 1;
	cdq(0, n + 1);
	printf("%d", f[n]);
	return 0;
}