#include <iostream>
#include <stdio.h>
/* run this program using the console pauser or add your own getch, system("pause") or input loop */

int main(int argc, char *argv[]){
	 // §é²{­È­pºâ
    int d,e,f;    
	float r;
	scanf("%d",&d);
	scanf("%d",&e);
	scanf("%f",&r);
    f=d/(1+r);
	f=f+e/((1+r)*(1+r));
	printf("Present value=%f\n",f);

	system("pause");
	return 0;
}
