func_code_string: #include <bits/stdc++.h>   using namespace std;   using ll = long long;   const int MAXN = 100010;   int N;   int A[MAXN];   int main() {     ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);     cin >> N;     for (int i = 0; i < N; i++) {       cin >> A[i];     }     ll ans = 0;     for (int i = 0; i < N; i++) {       ans += ll(A[i]) * (N + 1 - A[i]);     }     for (int i = 0; i < N - 1; i++) {       ans -= ll(min(A[i], A[i + 1])) * (N + 1 - max(A[i], A[i + 1]));     }     cout << ans << endl;     return 0;   }   