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#include <fstream>
using namespace std;
ifstream in("mins.in");
ofstream out("mins.out");
typedef long long I64;
const int N = 1e6 + 5;
int n, m, d[N];
I64 sol, M;
bool no[N];
int main()
{
in >> m >> n;
m--, n--;
sol = 1LL * m * n;
M = max(m, n);
for (I64 i = 2; i <= M; ++i)
{
if (d[i])
continue;
d[i] = 1;
for (int j = i * 2; j <= M; j += i)
d[j]++;
for (I64 j = i * i; j <= M; j += i * i)
no[j] = 1;
}
for (int i = 2; i <= M; ++i)
if (!no[i])
sol -= 1LL * (d[i] % 2 ? 1 : -1) * (m / i) * (n / i);
out << sol << '\n';
}