#include <bits/stdc++.h>
using namespace std;
const int MAXN = 2000;
double F[2][MAXN + 1];
int main() {
  int n, t;
  double p;
  cin >> n >> p >> t;
  int x = 0, y = 1;
  F[x][0] = 1.0;
  fill(F[x] + 1, F[x] + n + 1, 0.0);
  for (int i = 0; i < t; ++i, swap(x, y)) {
    for (int j = 0; j <= n; ++j) {
      F[y][j] = 0.0;
      if (j == n) {
        F[y][j] += F[x][j];
      } else {
        F[y][j] += F[x][j] * (1 - p);
      }
      if (j - 1 >= 0) {
        F[y][j] += F[x][j - 1] * p;
      }
    }
  }
  double res = 0.0;
  for (int i = 0; i <= n; ++i) {
    res += i * F[x][i];
  }
  printf("%.12lf\n", res);
  return 0;
}
