#include <iostream>
#include<climits>
using namespace std;


int main()
{
    long long i,aux,au,a,b,s,ax,bx,min,in;
    cin>>a;
    cin >> b;
    min = INT_MAX;
    in =0;
    for (i=0;i<=a*b;++i)
    {
        ax = a+i;
        bx = b+i;
        aux = ax;
        au = bx;
        while (ax!=bx)
        {
            if (ax<bx)
                bx = bx-ax;
            else
                ax = ax-bx;
        }
        s = (aux*au)/ax;
        if (s<min)
        {
            min = s;
            in = i;
            if ((min == au) or (min == aux))
            {
                break;
            }

        }
    }
    cout<<in;
    return 0;
}