#include <iostream>
using namespace std;

int main()
{
    int n, m, sum = 0;
    cin >> n >> m;
    n = n - 1;
    m = m - 1;
    int i = 1, k = 1;
    double tg1, tg2;
    tg1 = (double)n / m;
    while (i <= n && k <= m)
    {
        tg2 = (double)i / k;
        if (tg1 > tg2)
        {
            i += 1;
            sum += 1;
        }
        else
        {
            if (tg1 < tg2)
            {
                k += 1;
                sum += 1;
            }
            else
            {
                if (tg1 == tg2)
                {
                    k += 1;
                    i += 1;
                    sum += 1;
                }
            }
        }
    }
    cout << sum << endl;
    return 0;
}