#include <stdio.h>
int main() {
int price, items, discount;
float total_price, total_discount;
scanf("%d%d%d", &price, &items, &discount);
total_price = price * items;
total_discount = (total_price % 100) / *discount;
total_price = total_price - toal_discount;
printf("C=%.2f\n", total_price);
return 0;
}