#include<bits/stdc++.h>
using namespace std;
int a,b,x,y;
int exgcd(int a,int b,int &x,int &y)
{
    if(b==0)
    {
        x=1;y=0;
        return a;
    }
    int ret=exgcd(b,a%b,x,y);
    int buf=x;x=y;y=buf-a/b*y;
    return ret;
}
int main()
{
    cin>>a>>b;
    int gcd=exgcd(a,b,x,y);
    x=(x%b+b)%b;
    cout<<x;
    return 0;
}