#include <cstdio>
#include <algorithm>
using namespace std;

typedef unsigned long long LL;
bool v[50011];
LL pre[50011], mu[50011], p[50011], cnt, n, m;
void get_mu(int n) {
    mu[1] = 1;
    pre[1] = 1;
    for (int i = 2; i <= n; i ++) {
        if(!v[i]) {
            p[++ cnt] = i;
            mu[i] = -1;
        }
        for (int j = 1; j <= cnt && p[j] * i <= n; j ++) {
            v[i * p[j]] = true;
            if (i % p[j] == 0) break;
            else mu[i * p[j]] = -mu[i];
        }
        pre[i] = pre[i - 1] + mu[i];
    }
}
int main() {
    get_mu(10000);
    scanf("%d%d", &n, &m);
    if (n > m) swap(n, m);
    LL ans = 0, t1, t2, l, r;
    for (LL i = 1; i <= n; i ++) {
        t1 = n / i;
        t2 = m / i;

        LL res = 0;
        for (l = 1; l <= t1; l = r + 1) {
            r = min(t1 / (t1 / l), t2 / (t2 / l));
            res += (pre[r] - pre[l - 1]) * (t1 / l) * (t2 / l);
        }
        ans += res * i;
    }

    printf("%lld", ans * 2ll - n * m);
    return 0;
}

第二个点WA了， 97123 89913 标准输出是 116501058067