program Takoyaki
 implicit none
 integer   :: n,x,t,ans

 read(*,*) n,x,t

 ans = 0
 
 do
  n = n - x
  ans = ans + t
 if ( n <= 0 ) then
  exit
 end if
 end do
  
 write(*,*) ans 
 
 
 end program Takoyaki


 

 