#include <bits/stdc++.h>
using namespace std;
double p, M[2222][2222];
int n, t;
int main() {
  cin >> n >> p >> t;
  n = min(t, n);
  for (int i = 0; i <= n; i++) M[0][i] = 0.0;
  for (int i = 0; i < t; i++)
    for (int j = 1; j <= n; j++) {
      M[i + 1][j] = M[i][j] * (1.0 - p) + (M[i][j - 1] + 1.0) * p;
    }
  printf("%.7lf", M[t][n]);
  return 0;
}
