implicit none
integer(8) A,X,Y,L
read(*,*) X
read(*,*) Y
read(*,*) L
if (mod(X,L)==0) then
    if (mod(Y,L)==0) then
        A=abs(X/L)+abs(Y/L)
    else
        A=abs(X/L)+abs(Y/L)+1
    end if
else
    if (mod(Y,L)==0) then
        A=abs(X/L)+1+abs(Y/L)
    else
        A=abs(X/L)+abs(Y/L)+2
    end if
end if

if (Y>=0) then
    if (X==0) then 
        A=A+0
    else
        A=A+1
    end if
else
    A=A+2
end if
write(*,*) A
end