#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx2")
#define _CRT_SECURE_NO_WARNINGS
#define debug(l) cerr<<" smotri huinyi : "<<#l<<' '<<l<<'\n';
#include "bits/stdc++.h"
//#include "geometry.h"
//#include "data_structure.h"
using namespace std;
using namespace chrono;
#define all(cnt) cnt.begin(), cnt.end()
#define allr(cnt) cnt.rbegin(), cnt.rend()
#define sqrt(l) sqrtl(l)
mt19937 rnd(std::chrono::high_resolution_clock::now().time_since_epoch().count());
typedef long long ll;
typedef long double ld;
signed main() {
#ifdef _DEBUG
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    ll a, b;
    cin >> a >> b;
    ll d = b * (b + 1) * (2 * b + 1) / 6;
    ll d0 = 0;
    if (a > 0) {
        a--;
        d0 = a * (a + 1) * (2 * a + 1) / 6;
    }
    cout << d - d0 << endl;
}