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

using ll = long long;
constexpr ll mod = 998244353, inv2 = (mod + 1) / 2;

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);
	}
	
	ll ans = 0;
	for(ll d = 1; d <= N; ++d) {
		const ll x = N / d, y = M / d;
		ans += x * (x + 1) / 2 % mod * y % mod * (y + 1) % mod * inv2 % mod * d % mod * d % mod * mu[d];
		if(ans < 0) ans += mod;
		if(ans >= mod) ans -= mod;
	}
	
	cout << ans << endl;
}