#include<fstream>
using namespace std;
ifstream fin("inversmodular.in");
ofstream fout("inversmodular.out");
void invmod(long long &x,long long &y,int a,int b){
    if(b==0)
        x=1,y=0;
    else{
        invmod(x,y,b,a%b);
        long long c=x;
        x=y;
        y=c-y*(a/b);
    }
}
int main(){
    long long a,b,x=0,y=0;
    fin>>a>>b;
    invmod(x,y,a,b);
    if(x<=0){
        x=b+x%b;
    }
    fout<<x;

}