#include <bits/stdc++.h>
using namespace std;
double eps = 1e-9;
bool isEqual(double a, double b) { return (abs(a - b) < eps); }
int main() {
  ios_base::sync_with_stdio(false);
  int i, j;
  double p;
  int n;
  cin >> n;
  ;
  cin >> p;
  int t;
  cin >> t;
  ;
  vector<double> prob(n + 1, 0.0);
  prob[0] = 1.0;
  for (i = 0; i < t; i++) {
    vector<double> curProb(n + 1, 0.0);
    double check = 0.0;
    for (j = 0; j < n + 1; j++) {
      if (j < n)
        curProb[j] = prob[j] * (1.0 - p);
      else
        curProb[j] = prob[j];
      if (j > 0) curProb[j] += (prob[j - 1] * p);
      check += curProb[j];
    }
    assert(isEqual(check, 1.0));
    prob = curProb;
  }
  double ans = 0;
  for (i = 1; i < n + 1; i++) ans += ((double)i * prob[i]);
  cout << setprecision(9) << fixed;
  cout << ans << '\n';
}
