adun_20p

#include <iostream>
using namespace std;

int cmmmc(int a,int b)
{
    int x=a,y=b,r;
    long int p=a*b;
	while(y)
        r=x%y,x=y,y=r;
	return p/x;
}

int main()
{
    int x,y;
    cin>>x>>y;
    if(x>y)
        swap(x,y);
    long int c,cmax=1000000000,sol;
    for(int k=y-x;k>=0;--k)
    {
        c=cmmmc(x+k,y+k);
        if(c<cmax)
            cmax=c,sol=k;
    }
    cout<<sol;
    return 0;
}