#include<bits/stdc++.h>
#define ll long long
using namespace std;
ll gcd(ll a, ll b)
{
    return b == 0 ? a : gcd(b, a%b);
}
ll extended_gcd(ll a, ll b, ll &x, ll &y)
{
    if(!b)
    {
        x = 1;
        y = 0;
        return a;
    }
    ll ret = extended_gcd(b, a%b, x, y);
    ll tmp = x;
    x = y;
    y = tmp-a/b*y;
    return ret;
}
int main()
{
    ll a, b, t, x, y, z;
    freopen("mod.in","r",stdin);
	freopen("mod.out","w",stdout);
    scanf("%lld%lld", &a, &b);
    z = extended_gcd(a, -1*b, x, y);
    x /= z;
    y /= z;
    t = b/gcd(a, b);
    printf("%lld\n", (x%t+t)%t);
	return 0;
}