#include<cstdio>

 #include<cstring>

 #include<cmath>

 #include<algorithm>

 typedef long long ll;

 using namespace std;

 ll x,y;

 void exgcd(ll a,ll b)

 {

     if(b==)

     {

         x=;

         y=;

         return;

     }

     exgcd(b,a%b);

     ll

     sb=x;

     x=y;

     y=sb-(a/b*y);

 }

 void solve(ll a,ll b)

 {

     exgcd(a,b);

     printf("%lld",(x+b)%b);//最小正整数解

 }

 int main()

 {

     ll a,b;

     scanf("%lld%lld",&a,&b);

     solve(a,b);

     return ;

 }