#include <bits/stdc++.h>
using namespace std;
ifstream in("input.txt");
const int mod = 1e9 + 9, SIZE = 300005;
const int N = 2005;
double dp[N][N];
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int n, t;
  double p;
  cin >> n >> p >> t;
  cout << fixed << setprecision(9);
  dp[0][0] = 1.0;
  for (int i = 1; i <= t; i++) {
    for (int j = 0; j <= n; j++) {
      if (j) dp[i][j] += dp[i - 1][j - 1] * p;
      double nobody_boards = 1.0 - p;
      if (j == n) nobody_boards = 1.0;
      dp[i][j] += dp[i - 1][j] * nobody_boards;
    }
  }
  double ans = 0.0;
  for (int j = 1; j <= n; j++) {
    ans += (double)j * (dp[t][j]);
  }
  cout << ans << "\n";
  return 0;
}
