#include <bits/stdc++.h>
using namespace std;
const int N = 1e6 + 7;
const int inf = 0x3f3f3f3f;
const long long INF = 0x3f3f3f3f3f3f3f3f;
const int mod = 1e9 + 7;
const double eps = 1e-8;
const double PI = acos(-1);
int n;
long long h[N], dp[N][2];
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) scanf("%lld", &h[i]), h[i]--;
  h[n + 1] = inf;
  dp[1][0] = h[1];
  dp[1][1] = min(h[1], h[2]);
  long long ans = dp[1][0];
  for (int i = 2; i <= n; i++) {
    dp[i][0] = (dp[i - 1][1] * min(h[i - 1], h[i]) + h[i]) % mod;
    dp[i][1] = ((dp[i - 1][1] * min(h[i - 1], min(h[i], h[i + 1])) % mod) +
                min(h[i], h[i + 1])) %
               mod;
    ans = (ans + dp[i][0]) % mod;
  }
  printf("%lld\n", ans);
  return 0;
}
