#include <iostream>

using namespace std;


int main()
{
    int i;
    int a,b,s,aa,bb,mini,in;
    cin>>a;
    cin >> b;
    mini = 1000000000;
    in =0;
    for (i=0;i<=a*b;++i)
    {
        aa = a+i;
        bb = b+i;
        while (aa!=bb)
        {
            if (aa<bb)
                bb = bb-aa;
            else
                aa = aa-bb;
        }
        s = (a*b)/aa;
        if (s<mini)
        {
            mini = s;
            in = i;
        }
    }
    cout<<in;
    return 0;
}