#include <bits/stdc++.h> using namespace std; using ll = long long; const int INF = (int)1e9 + 1001010; const ll llINF = (long long)4e18 + 22000020; const string endn = "\n"; template <class T> inline auto vector2(size_t i, size_t j, const T &init = T()) { return vector(i, vector<T>(j, init)); } const string ELM_SEP = " ", VEC_SEP = endn; template <class T> istream &operator>>(istream &i, vector<T> &A) { for(auto &I : A) i >> I; return i; } template <class T> ostream &operator<<(ostream &o, const vector<T> &A) { int i = A.size(); for(const auto &I : A) o << I << (--i ? ELM_SEP : ""); return o; } template <class T> ostream &operator<<(ostream &o, const vector<vector<T>> &A) { int i = A.size(); for(const auto &I : A) o << I << (--i ? VEC_SEP : ""); return o; } template <class T> vector<T> &operator++(vector<T> &A, int) { for(auto &I : A) I++; return A; } template <class T> vector<T> &operator--(vector<T> &A, int) { for(auto &I : A) I--; return A; } template <class T, class U> bool chmax(T &a, const U &b) { return ((a < b) ? (a = b, true) : false); } template <class T, class U> bool chmin(T &a, const U &b) { return ((a > b) ? (a = b, true) : false); } ll floor(ll a, ll b) { if(b < 0) a = -a, b = -b; return (a >= 0) ? a / b : (a + 1) / b - 1; } ll ceil(ll a, ll b) { if(b < 0) a = -a, b = -b; return (a > 0) ? (a - 1) / b + 1 : a / b; } ll bit(unsigned long long val, unsigned long long digit) { return (val >> digit) & 1; } #ifdef DEBUG #include <cpp-dump/dump.hpp> #define dump(...) cpp_dump(__VA_ARGS__) namespace cp = cpp_dump; struct InitCppDump { InitCppDump() { if(!isatty(fileno(stderr))) CPP_DUMP_SET_OPTION(es_style, cpp_dump::es_style_t::no_es); CPP_DUMP_SET_OPTION(log_label_func, cp::log_label::line()); CPP_DUMP_SET_OPTION(max_iteration_count, 30); } } init_cpp_dump; #else #define dump(...) #endif // ==================== ここまでテンプレ ==================== int main(int argc, char *argv[]) { ios::sync_with_stdio(false); cin.tie(nullptr); ll n; cin >> n; vector<ll> a(n); cin >> a; if(n > 100) exit(1); ll ans = 0; for(int i = 0; i < n; i++) { for(int j = 0; j < n; j++) { ll add = abs((i + 1) - (j + 1)) * abs(a[i] - a[j]); ans += add; } } cout << ans << endl; return 0; }