#include <bits/stdc++.h>
using namespace std;
double dp[2002][2002];
int main() {
  int n, t;
  double p;
  cin >> n >> p >> t;
  dp[0][0] = 1;
  for (int i = 0; i <= t; i++) {
    for (int j = 0; j <= n; j++) {
      if (j < n)
        dp[i + 1][j + 1] += dp[i][j] * p;
      else
        dp[i + 1][j] += dp[i][j] * p;
      dp[i + 1][j] += dp[i][j] * (1 - p);
    }
  }
  double ans = 0;
  for (int i = 0; i <= n; i++) {
    ans += (dp[t][i] * i);
  }
  printf("%.6f\n", ans);
}
