#include <bits/stdc++.h>
using namespace std;
double dp[2005][2005];
int main() {
  ios::sync_with_stdio(0);
a:
  int n, t;
  double p;
  cin >> n >> p >> t;
  dp[0][0] = 1.0;
  for (int i = 1; i <= t; i++) dp[i][0] = dp[i - 1][0] * (1.0 - p);
  for (int j = 1; j <= n; j++) dp[0][j] = 0.0;
  for (int i = 1; i <= t; i++) {
    for (int j = 1; j <= n; j++) {
      if (j == n)
        dp[i][j] = dp[i - 1][j - 1] * p + dp[i - 1][j];
      else
        dp[i][j] = dp[i - 1][j - 1] * p + dp[i - 1][j] * (1.0 - p);
    }
  }
  double res = 0.0;
  for (int i = 0; i <= n; i++) res += (dp[t][i] * ((double)i));
  printf("%.10f\n", (double)res);
}
