ll gcd(ll a, ll b) {
    if (!b) return a;
    return gcd(b, a % b);
}

ll lca(ll a, ll b) {
    return a * b / gcd(a, b);
}

class PyramidSequences {
public:
    static long long distinctPairs(int n, int m) {
        ll N = (ll)(n - 1), M = (ll)(m - 1);
        if (N < M) swap(N, M);
        ll X = lca(N, M);
        ll Y = X / M;
        ll ans = Y * M + 1;
            ll Z = (N + M - 1) / M;
            int pos = 0;
            for (int i = 0; Y > 0; i++) {
                bool fl = !((N - pos) / M >= Z - 1);
                ans -= i * min(Y, Z - (int)fl);
                    Y -= Z - (int)fl;
                    pos = (pos + (Z - (int)fl) * M) % N;
            }
            return ans;
    }
};