#include <fstream>

using namespace std;

int main()
{
  ifstream cin ("cautbin.in");
  ofstream cout ("cautbin.out");
  int li,ls,gasit=false,x,mij,V[1000];
  cin>>li>>ls;
  while(li<=ls)
  {
      mij=(li+ls)/2;
      if(x==V[mij]) {gasit=true;break;}
      else if(x<V[mij]) ls=mij-1;
                       else li=mij+1;}

 if(gasit=true)
    cout<<mij;

    return 0;
}