#include <bits/stdc++.h>
using LL = __int128;

const int maxn = 1e6 + 5;

LL read() {
	LL s = 0,f = 1;
	char c = getchar();
	for(;c < '0'||c > '9';c = getchar())
		if(c == '-')f = -1;
	for(;c >= '0'&&c <= '9';c = getchar())
		s = (s << 1) + (s << 3) + (c ^ '0');
	return s * f;
}

void write(LL x) {
	if(x > 9)
		write(x / 10);
	putchar(x % 10 + '0');
	return ;
}

int main() {
	freopen("chessqueen.in","r",stdin);
	freopen("chessqueen.out","w",stdout);
	LL n = read(),m = read();
	if(n > m)
		std::swap(n , m);
	write(n * m * (m + n - 2) + 2 * (2 * ((n - 1) * n * (2 * n - 1) / 6 - n * (n - 1) / 2) + (m - n + 1) * n * (n - 1)));
	return 0;
}