#include <cstdio>

void euclid(int a,int b,int &d,int &x,int &y){
    if(b==0){
        x=1;
        y=0;
        d=a;} else {
            int x0,y0;
            euclid(b,a%b,d,x0,y0);
            x=y0;
            y=x0-a/b*y0; }
}

int main(){
    int a,b,d,x,y;
    freopen("inversmodular.in","r",stdin);
    freopen("inversmodular.out","w",stdout);
        scanf("%d %d",&a,&b);
        euclid(a,b,d,x,y);
        if(x>0)printf("%d\n",x); else printf("%d\n",x-(x/b+(x%b))*b);
}