#include < stdio.h >
using namespace std;
int main()
{
  int a,b,c;
  scanf("%d%d",&a,&b); //a=3,b=13
  c=a+(b-a)/2;
  /*
   the length of the interval is b, the mean length is (b-a) / 2, so that we get to the regular number,
   to the initial one and add the middle of the length of the interval
   c=3+(13-3)/2=3+5=8
​  */
  printf("%d",c);
  return 0;
}