#include<stdio.h>
#include<math.h>
int main(){
    double P,R,N;
    int N;
    scanf("%lf %lf %d", &P, &R, &N);
        if(N==0){
    printf("Invalid input");
    return 0;
        }
        R=R/(12*100);
        double EMI=(P*R*pow(1+R,N))/(pow(1+R,N)-1);
        printf("%.2f",EMI);
        return 0;
}