#include <iostream>
#include <cstdlib>
#include <string>
#include <math.h>
#include <vector>

using namespace std;

int main ()
{
   float c;int b;cin>>b>>c;
for(int i=0;i<c*b;i++)
{ if((i/b>=c-1)&&(i/b<=c+1))
{cout<<i+1;
break;}}


    
     return 0;
}