#include <bits/stdc++.h>
using namespace std;
inline void splay(long long &v) {
  v = 0;
  char c = 0;
  int p = 1;
  while (c < '0' || c > '9') {
    if (c == '-') p = -1;
    c = getchar();
  }
  while (c >= '0' && c <= '9') {
    v = (v << 3) + (v << 1) + c - '0';
    c = getchar();
  }
  v *= p;
}
long long a[1000010];
long long dp[1000010], ans;
int main() {
  long long n;
  splay(n);
  for (int i = 1; i <= n; i++) {
    splay(a[i]);
    a[i]--;
  }
  dp[1] = min(a[1], a[2]);
  ans += a[1];
  for (int i = 2; i <= n; i++) {
    ans += a[i];
    long long x = min(a[i], a[i - 1]);
    long long y = min(x, a[i + 1]), z = min(a[i], a[i + 1]);
    ans += dp[i - 1] * x;
    dp[i] = dp[i - 1] * y + z;
    ans %= 1000000007LL;
    dp[i] %= 1000000007LL;
  }
  cout << ans << endl;
}
