#include #define rep(i, a) for (int i = (int)0; i < (int)a; ++i) #define rrep(i, a) for (int i = (int)a - 1; i >= 0; --i) #define REP(i, a, b) for (int i = (int)a; i < (int)b; ++i) #define RREP(i, a, b) for (int i = (int)a - 1; i >= b; --i) #define pb push_back #define eb emplace_back #define all(x) x.begin(), x.end() #define rall(x) x.rbegin(), x.rend() using ll = long long; constexpr ll mod = 1e9 + 7; constexpr ll INF = 1LL << 60; template inline bool chmin(T &a, T b) { if (a > b) { a = b; return true; } return false; } template inline bool chmax(T &a, T b) { if (a < b) { a = b; return true; } return false; } ll gcd(ll n, ll m) { ll tmp; while (m != 0) { tmp = n % m; n = m; m = tmp; } return n; } ll lcm(ll n, ll m) { return abs(n) / gcd(n, m) * abs(m); //gl=xy } using namespace std; void solve() { int n; cin>>n; vectora(n); rep(i,n)cin>>a[i]; ll ans=0; rep(i,n)ans+=a[i]*(i+1)*(n-i); cout<