#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
int exgcd(int a,int b,int& x,int& y){
if(b==0){
x=1; y=0;
return a;
}
int res=exgcd(b,a%b,x,y);
int t=x;
x=y;
y=t-(a/b)*y;
return res;
}
int main(){
int a,b,x,y;
cin>>a>>b;
exgcd(a,b,x,y);
cout<<(x+b)%b<<endl;
return 0;
}