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

using namespace std;    

int main()    
{    
             double const a = 0.5,h = 1.2,k = 0.6;    
             int const b = 25, c = 12;    
             double xi,x,e = 2.71,r,f;    
                      
                      
             while ((a <= xi )&& (xi <= b))
                   {    
                   x = xi+h;    
                     if (xi > c)    
                      r=pow((xi*e),(k*pow(a*b,0.5 )));
                      else    
                      f=xi+tan(pow(x,2.0));    
                   }    
                   cout<<" f= " <<f;
             return 0 ;
}