#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int main(){
    int x,y,l;
    scanf("%d %d %d", &x, &y, &l);
    printf("%d\n", (int)ceil( (double)abs(x)/l ) + (int)ceil( (double)abs(y)/l ));

    return 0;
}