#include <bits/stdc++.h>

 const int INF = 0x3f3f3f3f;

 inline void read(int &x)

 {

     x = ;char ch = getchar();char c = ch;

     while(ch < '' || ch > '')c = ch, ch = getchar();

     while(ch <= '' && ch >= '')x = x *  + ch - '',ch = getchar();

     if(c == '-')x = -x;

 }

 void exgcd(int a,int b,int &x,int &y)

 {

     if(!b){x = ;y = ;}

     else

     {

         exgcd(b, a%b, y, x);

         y -= a/b * x;

     }

 }

 int a,b;

 int main()

 {

     read(a);read(b);

     int x = ,y = ;

     exgcd(a, b, x, y);

     printf("%d", ((x%b) + b)%b);

     return ;

 }