#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
#define REP(i, n) for(int i=0; i<n; i++)
#define REPi(i, a, b) for(int i=int(a); i<int(b); i++)
#define MEMS(a,b) memset(a,b,sizeof(a))
#define mp make_pair
#define MOD(a, m) ((a % m + m) % m)
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
const ll MOD = 1e9+7;

int main(){
    ll L, R;
    cin >> L >> R;

    ll ans = 0;

    vector<ll> G(R+1);
    for(ll g = R; g >= 2; g--){
        /// [left, right)
        //ll left = (L + g - 1) / g;
        //ll left = L/g + (L % g != 0);
        ll left = (L-1)/g;
        ll right = R / g;

        //ll n = (right - left + 1) * (right - left + 1);
        ll n = (right - left) * (right - left);
        for(ll k = 2*g; k <= R; k += g){
            n -= G[k];
        }

        G[g] = n;

        //prllf("%d: %d, %d, %lld\n", g, left, right, n);

        ans += n;
    }

    //cout << ans << endl;

    for(ll x = L; x <= R; x++){
        if(x == 1) continue;
        for(ll y = x; y <= R; y += x){
            if(x == y) ans -= 1;
            else ans -= 2;
        }

        //ans -= R/x * 2 - 1;
    }

    cout << ans << endl;
    return 0;
}

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
template <typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

#ifndef aa
#define trace(...)
#define endl '\n'
#endif
#define pb push_back
#define ub upper_bound
#define lb lower_bound
#define fi first
#define se second
#define int long long
typedef long long ll;
typedef long double ld;
#define pii pair<int,int>
#define pll pair<ll,ll>
#define sz(x) ((long long)x.size())
#define fr(a,b,c) for(int a=b; a<=c; a++)
#define frev(a,b,c) for(int a=c; a>=b; a--)
#define rep(a,b,c) for(int a=b; a<c; a++)
#define trav(a,x) for(auto &a:x)
#define all(con) con.begin(),con.end()
#define done(x) {cout << x << endl;return;}
#define mini(x,y) x=min(x,y)
#define maxi(x,y) x=max(x,y)
const ll infl = 0x3f3f3f3f3f3f3f3fLL;
const int infi = 0x3f3f3f3f;
mt19937_64 mt(chrono::steady_clock::now().time_since_epoch().count());
//const int mod = 998244353;
const int mod = 1e9 + 7;
typedef vector<int> vi;
typedef vector<string> vs;
typedef vector<vector<int>> vvi;
typedef vector<pair<int, int>> vpii;
typedef map<int, int> mii;
typedef set<int> si;
typedef set<pair<int,int>> spii;
typedef queue<int> qi;
uniform_int_distribution<int> rng(10,1e7);

//DEBUG FUNCTIONS START
#define cerr cout
void __print(int x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}
template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifndef ONLINE_JUDGE
//#define deb(x...) cerr << "[" << #x << "] = "; _print(x)
#define deb(x...)  _print(x)
#else
#define deb(x...)
#endif
// DEBUG FUNCTIONS END

const int N = 2e5 + 5;



void solve(){
	
	int n;
	cin >> n;
	
	vi a(n);
	rep(i,0,n)
		cin >> a[i];
	
	int ans = 0, p0 = 0, p1 = 0;
	
	rep(i,0,n){
		ans += i * a[i] * a[i] + p0 - 2 * a[i] * p1;
		p0 += a[i] * a[i];
		p1 += a[i];
	}
	
	cout << ans;
	
}




signed main() {
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    cout << fixed << setprecision(15);
    int t = 1;
    //cin >> t;
    while (t--)
        solve();
    return 0;
}


int powm(int a, int b){
    int res = 1;
    while (b) {
        if (b & 1)
            res = (res*a) % mod;
        a = (a * a) % mod;
        b >>= 1;
    }
    return res;
}


int divide(int a, int b) {
    return (a % mod) * powm(b % mod, mod - 2) % mod;
}

 
int norm(int a) {
    while (a >= mod) a -= mod;
    while (a < 0) a += mod;
    return a;
}