#include <bits/stdc++.h>
                
using namespace std;

typedef long long ll;

int n;
ll mod = 1e9+7;
ll a[100005];
ll f[100005][6];

inline ll dfs(int step, int cnt)
{
    //cout << step << " " << cnt << '\n';
    if(cnt == 4)
        return 1;
    if(step > n)
        return 0;
    if(f[step][cnt] != -1)
        return f[step][cnt];
    ll ans = 0;
    ans = dfs(step+1,cnt)%mod;
    ans = (ans+a[step]*dfs(step+1,cnt+1)%mod)%mod;
    //cout << step << " " << cnt << " "<< ans << '\n';
    return f[step][cnt] = ans; 
}

int main()
{
    freopen("enumerate.in", "r", stdin);
    freopen("enumerate.out", "w", stdout);
            
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    
    memset(f,-1,sizeof(f));
    cin >> n;
    for(int i = 1; i <= n; ++i)
        cin >> a[i];
    
    cout << dfs(1,0);
        
   	return 0;
}