#include <bits/stdc++.h>
using namespace std;
double dp[2001][2001];
int main() {
  int n, t;
  double p;
  scanf("%d %lf %d", &n, &p, &t);
  dp[0][0] = 1;
  for (int i = 0; i <= n; i++) {
    for (int j = 1; j <= t; j++) {
      if (i == 0)
        dp[i][j] = dp[i][j - 1] * (1 - p);
      else if (i == n)
        dp[i][j] = dp[i][j - 1] + dp[i - 1][j - 1] * p;
      else
        dp[i][j] = dp[i][j - 1] * (1 - p) + dp[i - 1][j - 1] * p;
    }
  }
  double r = 0;
  for (int i = 0; i <= n; i++) {
    r += dp[i][t] * i;
  }
  printf("%.10lf\n", r);
  return 0;
}
