#include <iostream>
#include <stdio.h>

#define LL long long


using namespace std;
int Euclid(int a,int b)
{
    if(!b)
        return a;
    return Euclid(b,a%b);
}
LL n,m,x,y;
int c,res,d;
int main()
{

    //freopen("data.txt", "r", stdin);
    scanf("%d%d",&n,&m);
    if(n<m)
        swap(n,m);
    y=Euclid(n,m);
    x=m*(n/y);
    d=n-m;
    while(c<d)
    {
        n++;
        m++;
        c++;
        y=Euclid(n,m);
        //printf("%d ",m*(n/y));
        if(x>(m*(n/y)))
        {
            x=m*(n/y);
            res=c;
        }
    }
    printf("%d",res);
    return 0;
}