#include <bits/stdc++.h>
using namespace std;
#include <atcoder/modint>
using namespace atcoder;

using mint = modint998244353;

int main() {
	int N, M;
	cin >> N >> M;
	if(N > M) swap(N, M);
	
	vector<int> spf(N + 1, -1), mu(N + 1, 1);
	for(int i = 2; i <= N; ++i) {
		if(spf[i] == -1) for(int j = i; j <= N; j += i) if(spf[j] == -1) spf[j] = i;
		mu[i] = (i / spf[i] % spf[i] ? -mu[i / spf[i]] : 0);
	}
	
	auto f = [](int x) {
		return mint(x) * (x + 1) / 2;
	};
	
	mint ans = 0;
	for(int d = 1; d <= N; ++d) ans += mint(mu[d]) * d * d * f(N / d) * f(M / d);
	
	cout << ans.val() << endl;
}