#include <bits/stdc++.h>
using namespace std;
double dp[2222][2222];
int main() {
  int n, t, i, j;
  double p, q, answer = 0.0;
  scanf("%d%lf%d", &n, &p, &t);
  q = 1.0 - p;
  dp[0][0] = 1;
  for (i = 0; i <= n; i++)
    for (j = 1; j <= t; j++) {
      if (i == n)
        dp[i][j] += dp[i][j - 1];
      else
        dp[i][j] += dp[i][j - 1] * q;
      if (i >= 1) dp[i][j] += dp[i - 1][j - 1] * p;
    }
  for (i = 1; i <= n; i++) answer += double(i) * dp[i][t];
  printf("%.6lf\n", answer);
}
