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