#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, t;
  double p;
  cin >> n >> p >> t;
  vector<vector<double> > dp(2010, vector<double>(2010, 0));
  vector<vector<double> > now(2010, vector<double>(2010, 0));
  dp[0][0] = 1;
  for (int i = 0; i < t; i++) {
    for (int j = 0; j < n + 1; j++) {
      if (j == n) {
        dp[i + 1][j] += dp[i][j];
        continue;
      }
      dp[i + 1][j + 1] += dp[i][j] * p;
      dp[i + 1][j] += dp[i][j] * (1 - p);
    }
  }
  double fa = 0;
  for (int i = 0; i < n + 1; i++) fa += dp[t][i] * i;
  cout << setprecision(20) << fa;
  return 0;
}
