#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 x,y,n,m;
int c,res;
int main()
{

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