#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");
        return 0;
    }
    R = R / (12 * 100);
    double EMI = (P * R * pow(1 + R, N)) /
(pow(1 + R, N) - 1);
    printf("%.2lf", EMI);
    return 0;
}