// editor1
#include<stdio.h>
int main()
{
    int p,r,n;
    scanf("%d",&p);
    scanf("%d",&r);
    scanf("%d",&n);
     int emi=0;
     
     int R=(1+r)**n;
     int up=p*r*R;
     int down=R-1;
     emi=up/down;
     printf("%d",emi);
    
}