Sicily10330

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <list>
using namespace std;

int main()
{
	int n,m;
	scanf("%d%d",&n,&m);
	if (n%m==0)
	  printf("0\n");
  else
  {
    if (m%n==0)
      printf("%d\n",(m/n-1)*n);
    else
    {
    	int ans=0;
    	int total=0;
    	int counter=1;
    	int left=0;
    	while (counter<=n)
    	{
    		total=m+left;
    		if (total%n!=0)
    		{
    		  ans+=total/n;
    		  left=total-total/n*n;
    		}
  		  else
  		  {
  		    ans+=total/n-1;
    			left=0;
    		}
		    counter++;
    	}
    	printf("%d\n",ans);
    }
  }
}