#include <iostream>
#include <stdio.h>
using namespace std;
int v[1002][1002];
FILE *f,*g;
int main()
{
    int aux,m,n,con,egal;
    cin>>m;
    cin>>n;
    if(n>m)
    {
        aux=m;
        m=n;
        n=aux;
    }
    con=0;
    egal=0;
    while(egal==0)
    {
        if((m+con)%(n+con)==0)
        {
            egal=1;
        }
        con++;
    }
    con--;
    cout<<con;
}