/*
TASK:trade
LANG:C++
*/
#include <iostream.h>
#include <stdlib.h>
#include <iomanip.h>
int main()
{
  double a, b;
  cin >> a;
  cin >> a;
  cin >> a;
  cin >> a;
  a=a;
  b=a+0.75;
  cout << setiosflags(ios::fixed) << setprecision(6) << b;
  return 0;
}





















