#include <bits/stdc++.h>
using namespace std;
const int MAX_N = 2005;
double probability[MAX_N][MAX_N];
int main() {
  int no_of_people, total_time;
  double new_person_probability;
  cin >> no_of_people >> new_person_probability >> total_time;
  double no_new_person_probability = 1 - new_person_probability;
  memset(probability, 0, sizeof(probability));
  probability[0][0] = 1;
  for (int t = 1; t <= total_time; t++) {
    probability[0][t] = no_new_person_probability * probability[0][t - 1];
    for (int i = 1; i < no_of_people; i++) {
      probability[i][t] = new_person_probability * probability[i - 1][t - 1] +
                          no_new_person_probability * probability[i][t - 1];
    }
    probability[no_of_people][t] =
        probability[no_of_people][t - 1] +
        new_person_probability * probability[no_of_people - 1][t - 1];
  }
  double expectation = 0;
  for (int i = 1; i <= no_of_people; i++)
    expectation += i * probability[i][total_time];
  cout << setprecision(7) << expectation;
  return 0;
}
