// editor1
#include<stdio.h>
#include<math.h>
int main()
{
    double P,R,N,emi;
    scanf("%lf %lf %lf",&P,&R,&N);
    if(N==0)
    {
        printf("Invalid input");
        return 0;
    }
    double r=R/(12*100);log(1+r));
    double pow_val = exp(N*);
    emi = (P*r*pow_val)/(pow_val-1);
    emi=floor((emi*100)+0.5)/100.0;
    printf("%.2lf",emi);
    return 0;
}