// Link ->
// Author -> Efat Sikder, IUBAT
#include "bits/stdc++.h"
using namespace std;

typedef long long int ll;
typedef unsigned long long l1;
typedef double db;

#define pi acos(-1)
#define prDouble(x, y) fixed << setprecision(y) << x
#define lcm(a, b) ((a * b) / __gcd(a, b))
#define fast_io                       \
    ios_base::sync_with_stdio(false); \
    cin.tie(NULL);                    \
    cout.tie(NULL)
#define mm(x, v) memset((x), v, sizeof(x));
#define pb push_back
#define mp make_pair
#define ff first
#define ss second
#define nl << "\n"
#define debug(x) cout << #x << " = " << x nl
#define casePrint(ans, cn) cout << "Case " << cn << ": " << ans nl

void solve(int caseNumber)
{
    ll n, m;
    cin >> n >> m;
    ll ans = n * m;
    ll mn = min(n, m);
    for (int i = 1; i < mn; i++)
    {
        ans += (n - i) * (m - i);
    }
    cout << ans nl;
}

void init_code()
{
    fast_io;

}

signed main()
{
    init_code();
    int testcase = 1;
    // cin >> testcase;
    for (int caseNumber = 1; caseNumber <= testcase; ++caseNumber)
    {
        solve(caseNumber);
    }
    return 0;
}