#include<stdio.h>
#include<algorithm>
using namespace std;
void euc(long long a,long long b,long long &d,long long &x,long long &y)
{
    if(b==0)
    {
        d=a;
        x=1;
        y=0;
    }
    else
    {
        long long x1,y1;
        euc(b,a%b,d,x1,y1);
            x=y1;
            y=x1-(a/b)*y1;
    }
}

long long a,b,r;

int main()
{
freopen("inversmodular.in","r",stdin);
freopen("invermodular.out","w",stdout);


       long long div=0,x=0,y=0;
        scanf("%lld%lld",&a,&b);
        euc(a,b,div,x,y);
      //  printf("%d! ",div);
      if(x<0)
        x+=b;
            printf("%lld\n",x);
}