// editor1
#include<stdio.h>
#include<math.h>

int main(){
    double P,R;
    int N;
    scanf("%lf %lf %d",&P,&R,&N);
    if(N==0){
        printf("Invalid Input \n");
        return 0;
    }
    double montlyRate =R/12*100);
    double EMI=(P*monthlyRate*pow(1+monthlyRate,N))/(pow(1+monthlyRate,N)-1);
    printf("%.2lf",EMI);
    return 0;
    
}