#include <bits/stdc++.h>
using namespace std;
const int N = 2005;
double dp[N][N];
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int n, t;
  double p;
  cin >> n >> p >> t;
  dp[0][0] = 1;
  for (int i = 1; i <= t; i++) {
    dp[i][0] = dp[i - 1][0] * (1 - p);
    double sum = dp[i][0];
    for (int j = 1; j < n; j++) {
      dp[i][j] = dp[i - 1][j - 1] * p + dp[i - 1][j] * (1 - p);
      sum += dp[i][j];
    }
    dp[i][n] = 1 - sum;
  }
  double sum = 0;
  for (int i = 0; i <= n; i++) sum += i * dp[t][i];
  cout << fixed << setprecision(10) << sum;
}
