#include<stdio.h>
#include<math.h>
double emi(int *p,int *r,int *n){
    int x =*p;
    float y=((*r)/100)/12;
    int z=*n;
    float a=x*y*pow((1+y),z);
    float b=pow((1+y),z)-1;
    double res=a/b;
    return res;
}
int main(){
    int p,n;
    float r;
    scanf("%d %f %d",&p,&r,&n);
    printf("%.2f",emi(&p,&r,&n));
    return 0;
}