#include<bits/stdc++.h>
using namespace std;
const int MODA=1e9+7;
const int MOD1=1000000009,MOD2=993244853;
struct hs
{
	int h1,h2;
	long long operator()()const{return 1ll*h1*MOD2+h2;}
	hs operator+(const hs &h)const{return (hs){(h1+h.h1)%MOD1,(h2+h.h2)%MOD2};}
	hs operator-(const hs &h)const{return (hs){(h1-h.h1+MOD1)%MOD1,(h2-h.h2+MOD2)%MOD2};}
	bool operator<(const hs &h)const{return h1==h.h1?h2<h.h2:h1<h.h1;}
};
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	vector<hs> pw(1111111);
	pw[0]=(hs){1,1};
	for(int i=1;i<=1000100;i++)
		pw[i]=pw[i-1]+pw[i-1];
	vector<hs> S(1111111);
	unordered_map<long long,int> mp;
	mp[S[0]()]=0;
	int n;
	cin>>n;
	vector<int> dp(n+5);
	dp[0]=1;
//	int lgn=19;
	vector<pair<int,int>> stk;//pos,val
	vector<int> a(n+5);
	vector<int> L(n+5),R(n+5);
	for(int i=1;i<=n;i++)
	{
		cin>>a[i];
		S[i]=S[i-1]+pw[a[i]];
//		int last=0;
		while(not stk.empty() and stk.back().second<=a[i])
		{
			L[i]=stk.back().first;
			stk.pop_back();
		}
		if(not stk.empty())R[stk.back().first]=i;
		stk.emplace_back(i,a[i]);
		/*
		int minv=1e9,prep=0;
		for(auto [p,v]:stk)
		{
			int lgl=31-__builtin_clz(i-prep);
			for(int t=v;t<=min(v+lgl,minv-1);t++)
			{
				hs preS=S[i]-pw[t];
				auto it=mp.find(preS());
				if(it!=mp.end())
				{
					dp[i]+=dp[it->second];
					dp[i]%=MODA;
				}
			}
			minv=v;
			prep=p;
		}
		*/
		mp[S[i]()]=i;
	}
	vector<vector<int>> G(n+5);
	function<void(int,int,int)> solve=[&](int l,int r,int pos)
	{
		if(pos-l<r-pos)
		{
			for(int i=l;i<=pos;i++)
			{
				int lgn=19,v=a[pos];
				for(int t=v;t<=v+lgn;t++)
				{
					hs preS=S[i-1]+pw[t];
					auto it=mp.find(preS());
					if(it!=mp.end() and it->second<=r)
					{
						G[it->second].push_back(i-1);
					}
				}
			}
		}
		else
		{
			for(int i=pos;i<=r;i++)
			{
				int lgn=19,v=a[pos];
				for(int t=v;t<=v+lgn;t++)
				{
					hs preS=S[i]-pw[t];
					auto it=mp.find(preS());
					if(it!=mp.end() and it->second>=l-1)
					{
						G[i].push_back(it->second);
					}
				}
			}
		}
		if(L[pos])solve(l,pos-1,L[pos]);
		if(R[pos])solve(pos+1,r,R[pos]);
	};
	solve(1,n,stk[0].first);
	for(int i=1;i<=n;i++)
	{
		for(auto v:G[i])
		{
//			cerr<<"found "<<v<<' '<<i<<endl;
			dp[i]=(dp[i]+dp[v])%MODA;
		}
	}
	cout<<dp[n]<<endl;
	
	return 0;
}