#include <bits/stdc++.h>
using namespace std;
double dp[2020][2020];
int main() {
  ios_base::sync_with_stdio(0);
  cin.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);
  for (int i = 1; i <= t; i++) {
    for (int j = 1; j <= i; j++)
      dp[i][j] = dp[i - 1][j] * (j >= n ? 1 : (1 - p)) + dp[i - 1][j - 1] * p;
  }
  double ans = 0;
  for (int i = 1; i <= (n < t ? n : t); i++) ans += i * (dp[t][i]);
  printf("%.10lf", ans);
  return 0;
}
