#include<stdio.h>
int i = 0,N,D,z1 = 0,sw = 0,count = 0;
int main(void){
     scanf("%d,%d",&N,&D);
     while(sw != 1){
          z1 = (z1 + D) % N;
          if(z1 == 0){
               sw = 1;
          }
          else{
               count++;
          }
     }
     printf("%d",count);
     return 0;
}